Chemical Bonding - Lakshya JEE AIR (2025) PDF

Lakshya JEE AIR (2025) Chemical Bonding CHEMICAL BONDING Note: Hydrogen bond is an extreme manifestation of dipole dipole interaction. PHYSICS WALLAH 1 ...

Lakshya JEE AIR (2025) Chemical Bonding CHEMICAL BONDING Note: Hydrogen bond is an extreme manifestation of dipole dipole interaction. PHYSICS WALLAH 1  CHEMICAL BONDING Vander waal’s forces:  These are the weakest type of inter molecular forces that exist among the chemical species which bring a significant change in physical properties.  These are non-directional, non-valence cohesive forces. These attractive forces being played between the two molecules, are independent of the presence of other molecules.  Solid, liquid or gaseous states of many molecules are explained on the basis of inter molecular forces other than covalent, ionic or metallic bonds. Although inert gases do not form any type of bond but may exist in liquid and solid states. This shows that the atoms of inert gases are attracted by each other through some type of intermolecular forces. These intermolecular forces are called Vander Waals forces. Types of Vander Waal's Forces: (1) Dipole-dipole interaction: The force of attraction between the oppositely charged poles of two polar molecules (for example : H2S, HCl, PH3 etc.) is called dipole-dipole attraction. Two type of arrangements: (a) Head to Tail (in gas): H− Cl−.......... H+ − Cl (E  r) H+ − Cl− (b) Anti parallel (in solid and liquid): (E  r) − + Cl − H  Anti parallel arrangement is better arrangement than Head to Tail arrangement, when (a) Thermal agitation is not too high (b) Molecule is not too fatty. (2) Dipole-induced dipole interaction: This type of cohesive forces occurs in a mixture of polar and non polar molecules. For example force of attraction between Cl2 and H2O.  Size of non polar molecules increases then interaction between molecules increases. (3) Instantaneous dipole-Induced dipole interaction: The weak intermolecular forces operating in similar non polar gaseous molecules are called London forces. These forces are very weak in nature and exists only at low temperature. For example weak intermolecular forces in F2, Cl2, N2, molecules and in nobal gases. [Notation: upward arrow () represent increasing value, down ward arrow () represent decreasing value] London forces present in both polar and non-polar species but dominate in non-polar molecule. [Size  LDF  attraction] LDF depends upon: (a) size (b) molecular mass (c) polarizable electron Other type of interaction: (1) Ion-dipole interaction: Polar molecules are attracted by ions. The negative pole is attracted by cation and positive pole attracted by the anion. Na+ Cl – – H + (ion) ( Polar ) PHYSICS WALLAH 2  CHEMICAL BONDING (2) Ion-induced dipole interaction: When non polar molecules come in contact with ions, its electron cloud gets polarized and the oppositely charged end of it is attracted by the ion. For example attraction between Na + and Cl2 molecule. Size of non-polar molecule increases, attraction force increases. Na+  Cl2 (ion) (non − polar ) Boiling point depends on molecular mass and interaction force between molecules. Boiling point ∝molecular mass   ∝Interaction between molecules   Bent’s rule: (i) A lone pair of electron prefers to occupy that hybrid orbital which has greater percentage of s- character. (ii) A more electronegative atom/group prefers to occupy that hybrid orbital which has smaller percentage of s-character. Ex. Draw the geometry of PCl3F2 Sol. Because highly electronegative atom occupy axial position (axial position has smaller percentage of s- character). Drago's rule: On the basis of experimental bond angles of certain molecules fulfilling the following three conditions, (i) Central atom belongs to third or lower period in periodic table (ii) Central atom must contain atleast one lone pair of electron (iii) Electronegativity of surrounding atom is < 2.5 Drago generalised that in such molecules justification of experimental bond angle can be made satisfactory if one considers no hybridisation, i.e., overlapping of almost pure atomic orbitals from central atom. In such molecules bond angle is approximately 90º. Group 15 Bond angle Group 16 Bond angle NH3 107º48' H2O 104º28' PH3 93º36' H2S 92º AsH3 91º48' H2Se 91º SbH3 91º18' H2Te 90.5º Right order of bond angle. (a) H2O > H2S > H2Se > H2Te (b) NH3 > PH3 > AsH3 > SbH3 Ex: PH3 PHYSICS WALLAH 3  CHEMICAL BONDING Electron deficient bonding: (1) Back bonding: Back bonding generally takes place when out of two bonded atoms one of the atom has vacant orbitals (generally this atom is from second or third period) and the other bonded atom is having some non-bonded electron pair(generally this atom is from the second period). Back bonding increases the bond strength and decreases the bond length. For example, in BF3 the boron atom completes its octet by accepting 2p-electrons of fluorine into 2p empty orbital. + F F F F F B F – B =F + – B =F B– = F  B F + F F F F F Vacant Filled 2p-orbital 2p-orbital Decrease in B–F bond length is due to delocalised p–p back bonding between filled p-orbital of F atom and vacant p-orbital of B atom. The extent of back bonding is much larger if the orbitals involved in the back bonding are of same size, for example the extent of back bonding in boron trihalides is as follows: BF3 > BCl3 > BBr3 > BI3 There is p-p back bonding in boron trihalide. The extent of back bonding decreases from BF 3 to BI3 because of increasing size of p-orbitals participating in back bonding that is from 2p(in F) to 5p(in I). (2) Bridge bonding: There are many compounds in which some electron deficient bonds are present apart from normal covalent bonds or coordinate bonds which are 2c-2e– bonds(two centre two electron bonds). These electron deficient bonds have less number of electrons than the expected such as three centre-two electron bonds (3c-2e) which are present in diborane B2H6, Al2(CH3)6, BeH2(s) etc. 97º Hb H Ht H H t H B B B B 122º Ht Ht H Hb H H B2 H 6 The structure of diborane containing four terminal(t) and two bridging(b) hydrogen atoms. The model determined by molecular orbital theory indicates that the bonds between boron and the terminal hydrogen atoms are conventional 2c-2e– covalent bonds. The bonding between the boron atoms and the bridging hydrogen atoms is, however different from that in molecules such as hydrocarbons. Having used two electrons in bonding to the terminal hydrogen atoms, each boron has one valence electron remaining for additional bonding. The bridging hydrogen atoms provide one electron each. Thus, the B2H2 ring is held together by four electrons, an example of 3c-2e– bonding. This type of bond is sometimes called as 'banana bond'. Group 13, gallium is known to form a similar compound, digallane, Ga2H6. But Al2Cl6 have covalent bond only and there is no electron deficient bonding as depicted in the given structure. Cl Cl Cl Al Al (Al – Cl – Al is 3c – 4e bond) Cl Cl Cl PHYSICS WALLAH 4  CHEMICAL BONDING Silicates: Silicates are metal derivatives of silicic acid, H4SiO4 or Si(OH)4. Silicates are formed by heating metal oxide or metal carbonates with sand, e.g. Na2CO3 ⎯⎯⎯⎯⎯⎯ Fused with sand SiO → Na4SiO4, Na2(SiO3)n, etc. 2 O– O– – O ⎯→ Oxygen Si. ⎯→ Silicon – O O– – O O– Plane projection of Silicate ion O– Silicates have basic unit of SiO44–, each silicon atom is bonded with four oxide ions tetrahedrally. There are following types of silicates Silicates Sharing of O-atom Contribution of O- General formula / Basic Tetrahedral atom/Basic unit Tetrahedral unit Ortho (neso) 0 4 SiO44– Pyro (closo) 1 3.5 Si2O7–6 Cyclic (cyclo) 2 3 (SiO3)n2n– (n = finite) Simple chain 2 3 (SiO3)n2n– (n = infinite) (pyroxene) Double chain 11  5.5  = 4  2  (3, 2) avg. = 2.5 (Si4O11)n6n– (amphibole) 2D or (sheet or 3 2.5 (Si2O5)n2n– phyllo) 3D (tecto) 4 2 (SiO2)n Structure of odd e– molecules: Free electron occupies the one sp3 orbital. (1) NO2 Structure: N N + + O O O O − – The free electron resides (2) CIO2 Structure: Cl at the 3d-orbital of Cl-atom + O O − sp3 (3) CIO3: Structure: Cl O O O PHYSICS WALLAH 5  CHEMICAL BONDING H (4) CH3: Structure: Sp2 C H H Pz(containing free electron) Free electron present In one sp3 hybrid orbital (5) CF3: Structure: C F F F Molecule do not exist: 1. Due to d- orbital contraction: PH5, SH4, SH6, XeH2, XeH4, ClI3, (SiH6)-2 2. Due to steric repulsion: BCl4−, B2Cl6, B2Br6, B2I6, B2F6, SCl6, SBr6, SI6, ICl7, ClI7, [SiCl6]−2 Hydrolysis: In hydrolysis of covalent molecules the nucleopilic centre of molecule is replaced by OH– group of water generally through nucleopilic substitution reaction. Ex. Hydrolysis of SiCl4 H H Cl O+ Cl Cl O − HCl Si Si– Cl ⎯⎯⎯ → Si Cl Cl + H H Cl Cl OH Cl Cl Cl Transition state + 3H2O – 3HCl OH Si HO OH HO Silicic acid Note: CCl4, NF3, is inert towards hydrolysis due to the absence of d orbital, but under drastic condition these molecules under goes hydrolysis. CCl4 + H2O ⎯⎯⎯⎯⎯ superheated → COCl2 + 2HCl Note: Hydrolysis of XeF2 & XeF4 takes place through with redox reaction. 1 XeF2 + H2O ⎯⎯→ Xe + 2HF + O2 2 3 3XeF4 + 6H2O ⎯⎯→ 2Xe + XeO3 + 12HF + O2 2 XeF6 + 3H2O ⎯⎯→ XeO3 + 6HF PHYSICS WALLAH 6  CHEMICAL BONDING Ionic compounds: Properties of ionic compound: (a) Physical state: Ionic compounds are hard, crystalline and brittle due to strong electrostatic force of attraction. Brittleness → {Same charged ions comes nearer. So they repell each other} Attraction Repusion (b) Isomorphism: The phenomenon of different ionic compounds, having same crystal arrangement of ions is termed as isomorphism Condition of Isomorphism: (i) Same charge on cation & anion between isomorphs (ii) Same radius ratio range of cation & anion between isomorphs (iii) Same number of water of crystalization between isomorphs Ex. (i) ZnSO4·7H2O, FeSO4·7H2O are isomorphous (ii) All alums are isomorphous (c) Boiling point and melting point: Ionic compounds have high boiling point and melting point due to strong electrostatic force of attraction among oppositely charged ions. (d) Conductivity: It depends on ionic mobility. (i) In solid state - No free ions - Bad conductor of electricity. (ii) In fused state or aqueous solution Due to free ions - Good conductor of electricity. Conductivity order: Solid state < fused state < Aqueous solution (e) Solubility: Ionic compounds are more soluble in polar solvalents and less soluble in non polar solvents. Solubility of ionic compounds in water mainly depends upon hydration energy & lattice energy. Que. Why does the solubility of alkaline earth metal hydroxides in water increase down the group? Ans. Among alkaline earth metal hydroxides, the anion being common, the cationic radius will influence the lattice enthalpy. Since lattice enthalpy decreases much more than the hydration enthalpy with increasing ionic size, the solubility increases as we go down the group. Que. Why does the solubility of alkaline earth metal carbonates and sulphates in water decrease down the group? Ans. The size of anions being much larger compared to cations, the lattice enthalpy will remain almost constant within a particular group. Since the hydration enthalpies decrease down the group, solubility will decrease as found for alkaline earth metal carbonates and sulphates. PHYSICS WALLAH 7  CHEMICAL BONDING Fajan's rule: Just as all the covalent bonds have some partial ionic character, the ionic bonds also have partial covalent character. The partial covalent character of ionic bonds was discussed by Fajans interms of the following rules:  The smaller the size of the cation and the larger the size of the anion, the greater the covalent character of an ionic bond.  The greater the charge on the cation, the greater the covalent character of the ionic bond.  For cations of the same size and charge, the one, with electronic configuration (n-1)dx ns0, typical of transition metals, is more polarising than the one with a noble gas configuration, ns2 np6, typical of alkali and alkaline earth metal cations.  The cation polarises the anion, pulling the electronic charge toward itself and thereby increasing the electronic charge between the two. This is precisely what happens in a covalent bond, i.e., buildup of electron charge density between the nuclei. The polarising power of the cation, the polarisability of the anion and the extent of distortion (polarisation) of anion are the factors, which determine the per cent covalent character of the ionic bond.  Polarisation power of a cation is usually called ionic potential or charge density. Charg e on cation Ionic potential  (phi) = Size of cation Application of the concept of polarisation: (a) To compare the covalent and ionic character of molecule (b) To compare the nature of oxide (c) To compare the electrical conductivity of ionic compounds (d) Tendency of the formation of complex compounds (e) To compare the thermal stability of metal salts (f) To compare the intensity of colour of compounds (g) To compare the solubility of heavier metal halide in water. Inert pair effect: In p-block elements the stability of the lower oxidation state increases on descending the group. Because increased effective nuclear charge holds ns electrons tightly due to poor shielding effect of inner d & f orbitals and thereby, restrict their (ns electrons) participation in bonding only np electrons take part in bond formation. As a result of this, +1 oxidation state of Tl is more stable than it's +3 oxidation state. Pb shows +2 stable oxidation state and Bi shows +3 stable oxidation state. For example: Group 13 Group 14 B (+3) C (+4) Al (+3) Si (+4) Ga (+3), (+1) Ge (+4), (+2) In (+3), (+1) Sn (+4), (+2) Tl (+3), (+1) Pb (+4), (+2) Order of stability: Tl+1 > In+1 > Ga+1 (due to inert pair effect) Order of stability: Pb+2 > Sn+2 > Ge+2 (due to inert pair effect) PHYSICS WALLAH 8  CHEMICAL BONDING Molecular Orbital Theory (MOT): Given by Hunds & Mulliken: (1) Two atomic orbital come nearer & then overlap each other to form two molecular orbitals (MO) (2) Combination of atomic orbital (AO) forms molecular orbital (MO) Types of molecular orbitals: Molecular orbitals of diatomic molecules are designated as (sigma), (pie), (delta) etc. In this nomenclature, the sigma () molecular orbitals are symmetrical around the inter molecular axis (assumed to be z-axis) while pi () molecular orbitals are not symmetrical. (a) s-s combination of orbitals: Molecular orbital Nodal plane Atomic Atomic orbital orbital Energy 1s * 1s 1s 1s * Antibonding sigma Molecular orbital 1s 1s 1s 1s 1s 1s Bonding sigma Molecular orbital (b) p-p combination of orbital(end to end overlap): Molecular orbital Nodal plane Atomic Atomic orbital orbital Energy *2 pz 2pz 2pz 1s * Antibonding sigma Molecular orbital 2pz 2pz 2 pz 2pz 2pz 2 pz Bonding sigma Molecular orbital (c) p-p combination of orbitals (side by side overlap): Molecular Nodal plane orbital Atomic Atomic orbital orbital 2px 2px *2 px Energy *2 px Antibonding pi Molecular orbital 2pz 2px 2 px 2 px 2px 2px Bonding pi Molecular orbital (d) s-p combination of orbitals: PHYSICS WALLAH 9  CHEMICAL BONDING Molecular orbital Nodal plane Atomic Atomic orbital orbital Energy *2 px *2 spz Antibonding pi 2s 2pz Molecular orbital 2 spz 2 spz Bonding sigma Molecular orbital (3) Energy of BMO < Energy of ABMO. (4) Molecular orbitals can be filled by electrons according to Aufbau, Hund's, Pauli's principle. (5) Energy order of the molecular orbitals of homonuclear di-atomic molecules. Note: Molecular orbital energy diagram for up to N2 (molecule having ≤ 14 electrons) 1s  1*s  2s  *2s  2 px = 2 py  2 pz  *2 px = *2 py  *2 pz Note: Molecular orbital energy diagram for O2 and F2 (molecule having > 14 electrons) 1s  1*s ;  2s  *2s  2 pz  2 px = 2 py  *2 px = *2 py  *2 pz *, * = antibonding molecular orbital ,  = bonding molecular orbital Ex. Why molecular orbitals have different order of energy in N2 & O2? Sol. s-p mixing Hint AO MO AO AO MO AO *2 p *2 p 2p *2 p *2 p 2p 2p *2 p *2 p 2p 2 p 2 p 2 p Energy 2 p Energy 2 p 2 p *2 p *2s 2p 2p 2s 2s 2 p *2s The correct MO energy-level diagram The correct MO energy-level diagram When s-p mixing is not allowed. When s-p mixing is not allowed, the energies of the sp and 2 p orbitals are reversed. Bond Order: Bond order can be defined as: PHYSICS WALLAH 10  CHEMICAL BONDING Nb − N a Bond order = 2 Nb = No. of electron in bonding MO's Na = No. of electron in antibonding MO's  If bond order = 0, it means species does not exist.  Bond order of 1, 2 & 3 corresponds to a single bond, double & triple bond respectively.  Bond order  stability of molecule  bond length  Magnetic behaviour:  If the molecule has one or more unpaired electron, it will be paramagnetic,  If all the electrons are paired it will be diamagnetic.  Magnetic strength can be calculated by using spin only formula of magnetic moment (μ).  μ= n(n+ 2) B.M. (where n = number of unpaired electron) Ex. H2 = Configuration: (1s) 2 , *0 (1s) Nb − N a 2 − 0 Bond order = = = 1, Hence H – H (diamagnetic) 2 2 PHYSICS WALLAH 11  CHEMICAL BONDING EXERCISE #1 Weak forces: 1. The correct order of boiling point of NCl3, NClF2, NF3 is: (A) NCl3 > NClF2 > NF3 (B) NCl3 < NClF2 < NF3 (C) NClF2 < NCl3 < NF3 (D) NCl3 < NF3 < NClF2 2. Which of the following option is correct about B.P.? (A) C3F8 < C3H8 (B) CH4 < CF4 (C) C2H6 > C2F6 (D) CF4< CH4 3. At room temperature, iodine is solid, Bromine is liquid and chlorine exist in gaseous phase due to following factor: (A) Surface area (B) Molecular volume (C) Ease of polarisation (D) All of these 4. Graphite is used as lubricant in high temperature machinery because: (A) Hexagonal layers slide over each other. (B) In between two-layer Vandar Waal Force is present. (C) Both A & B (D) None 5. Dipole-induced dipole interaction depends upon (A) Size of polarisable particle (B) Dipole moment of permanent dipole (C) Both (A) and (B) (D) None of these 6. Which of the following interaction is responsible for the formation of clathrates compounds: (A) Instantaneous dipole-induced dipole interaction (B) Ion-dipole interaction (C) Dipole-dipole interaction (D) Dipole-induced dipole interaction 7. Which of the following statement is correct? (A) Noble gases are insoluble in water. (B) The solubility of noble gases in water is fairly high due to London dispersion force. (C) The solubility of noble gases increases with the decrease in size of the noble gas atom. (D) The solubility of noble gases in water is fairly high due to dipole- induced dipole interaction. 8. Which of the following interaction is present in Xe.H2O: (A) Keesom force (B) Debye force (C) Ion-dipole (D) None of these Bent's rule and drago's : 9. Which of the following order of bond angle is CORRECT: (A) NH3 < PH3 < AsH3 < SbH3 (B) H2O < H2S < H2Se < H2Te (C) OF2 < H2O < Cl2O (D) SiF4 < SiCl4 < SiBr4 < SiI4 PHYSICS WALLAH 12  CHEMICAL BONDING 10. Calculate the percentage of p character in the orbital occupied by the lone pair of electrons in water molecule. [Given: HOH is 104. 5 and cos (104.5º) = –0.25] (A) 80% (B) 20% (C) 70% (D) 75% 11. Which of the following statement is correct for F3C – CF2 – CF3? (A) All C–F bond lengths are identical. (B) Two C–F bond attached to middle carbon atom are longer as compared to the other C–F bond at the terminal carbon. (C) Two C–F bonds attached to the middle carbon atom are shorter as compared to the other C–F bond at the terminal carbon. (D) None of these 12. The correct order of dC–H in the following option is (A) CHF3 = CH2F2 = CH3F (B) CHF3 > CH2F2 > CH3F (C) CH2F2 > CH3F > CHF3 (D) CH3F > CH2F2 > CHF3 13. The strongest P–O bond is found in the molecule: (A) F3PO (B) Cl3PO (C) Br3PO (D) (CH3)3PO 14. Consider the following compounds: (I) ClF3 (II) BrF3 The order of the angles between axial and equatorial bond pairs is: (A) I > II (B) I < II (C) I = II (D) none 15. Out of C2H6, C2H4 and C2H2. Compound which have highest C-C bond length is: (A) C2H4 (B) C2H2 (C) C2H6 (D) All have equal C-C bond length 16. The correct sequence for polarity of the following molecule: 1. Benzene 2. Inorganic Benzene 3. PCl3F2 4. PCl2F3 (P stands for polar and NP stands for non–polar) 1 2 3 4 (A) P NP NP P (B) NP NP NP P (C) NP P NP P (D) NP P P NP 17. N2H4 reacts with conc. H2SO4 to produce a salt [NH3 –NH3]+2 SO4–2 in which. (A) dN–N (salt) > dN–N (N2H4) (B) dN–N (salt) < dN–N (N2H4) (C) dN–N (salt) = dN–N (N2H4) (D) Cannot be predicted Back bonding: 18. The approximate hybridisation of the oxygen atom in disiloxane, (SiH3)2O, is: (A) sp2 (B) sp3 (C) sp (D) sp3d PHYSICS WALLAH 13  CHEMICAL BONDING 19. Which of the following will not form adduct? (A) (CH3)2O + BF3 (B) (SiH3)2O + BF3 (C) NH3 + BF3 (D) CH3NH2 + BF3 20. Select the correct statement about the reaction: BF3 + NH3 → BF3.NH3 (A) Octet of 'N' is incomplete in product (B) Octet of boron is complete in product (C) During the reaction total number of sigma bonds remain same in the reactant as well as in the product (D) Type of -bond between boron and nitrogen is 2p – 2p 21. Which of the following has highest bond energy? (A) C-F (CF4) (B) C-Cl (CCl4) (C) C-Br (CBr4) (D) B-F (BF3) 22. The incorrect statement regarding O(SiH3)2 and OCl2 molecule is/are: (A) The strength of back bonding is more in O(SiH3)2 molecule than OCl2 molecule (B) Si— O —Si bond angle in O(SiH3)2 is greater than Cl— O —Cl bond angle in OCl2 (C) The nature of back bond in both molecules is 2p – 3d (D) Hybridisation of central O-atom in both molecules is same 23. The direction of back bonding from surrounding atom to central atom is observed in which of the following compound (A) CCl3 (B) C(CN)3 (C) :CCl2 (D) [B(OH)4]– Multicentered bond / bridge bonding: 24. Which of the following molecule has 3C – 4e- bond? (A) Al2Cl6 (B) Be2Cl4 (C) I2Cl6 (D) All are having 3C – 4e- bond 25. In which of the following molecules/species all following characteristics are found? (a) Tetrahedral hybridisation (b) Hybridisation can be considered to have taken place with the help of empty orbital(s). (c) All bond lengths are identical i.e. all A–B bond lengths are identical. (A) B2H6 (B) Al2Cl6 (C) BeCl2 (g) (D) BF4– 26. The number of three centre two electron bonds in a molecule of diborane is: (A) 0 (B) 2 (C) 4 (D) 6 27. Which of the following ligand is not responsible for symmetrical bond cleavage in B2H6? (A) Me2S (B) H– (C) THF (D) NH3 28. Which of the following have both 3c–2e and 2c–2e type of bond? (A) BeH2(s) (B) BeCl2(s) (C) Al2H6 (D) Si2Cl6 29. Which of the following molecule have 3C–4e- bond as well as planar geometry? (A) Al2Br6 (B) Al2I6 (C) I2Cl6 (D) (AlH3)n PHYSICS WALLAH 14  CHEMICAL BONDING Silicate: 30. A cyclic silicate anion is represented as [Si3O9]n–. The value of 'n' is: (A) 3 (B) 4 (C) 6 (D) 8 31. In which of following silicate structure, the number of corner shared per tetrahedron is '2'. (A) Four membered cyclic silicate (B) Pyrosilicate (C) Orthosilicate (D) 2D-Silicate 32. If four SiO4 units are forming single chain type arrangement then find the total number of unshared 'O' atom. (A) 10 (B) 6 (C) 2 (D) 8 33. Thortvetite, Sc2Si2O7 is: (A) a pyrosilicate (B) a sheet slilicate (C) an orthosilicate (D) an amphibole Odd electron species: 34. Find the odd electron specie in which odd electron is present in pure 'p' atomic orbital. (A) NO 2 (B) ClO 2 (C) CF3 (D) CH3 Hydrolysis: 35. Which of the following is an uncommon hydrolysis product of XeF2 and XeF4? (A) Xe (B) XeO3 (C) HF (D) O2 36. In which of the following reactions is INCORRECT according to its products formed. (A) PCl3 + 3H2O → H3PO3 + 3HCl (B) NCl3 + 3H2O → NH3 + 3HOCl (C) ICl + H2O → HClO + HI (D) N2O4 + H2O → HNO3 + HNO2 37. Which of the following compound produce only oxyacid on hydrolysis: (A) IF7 (B) XeF6 (C) P4O6 (D) CrO2Cl2 38. Which of the following compound does not undergoes in partial hydrolysis? (A) BF3 (B) SiF4 (C) SbCl3 (D) NF3 39. The correct increasing order of extent of hydrolysis is: (A) CCl4 < MgCl2 < AlCl3 < SiCl4 < PCl5 (B) CCl4 < AlCl3 < MgCl2 < PCl5 < SiCl4 (C) CCl4 < SiCl4 < PCl5 < AlCl3 < MgCl2 (D) CCl4 < PCl5 < SiCl4 < AlCl3 < MgCl2 40. XeF6 on complete hydrolysis gives: (A) Xe (B) XeO2 (C) XeO3 (D) XeO4 Molecule does not exist: 41. Which of the following molecule does not exist? (A) PbI2 (B) VI3 (C) ClF7 (D) CuI PHYSICS WALLAH 15  CHEMICAL BONDING Inert pair effect: 42. Which of the following statements is incorrect? (A) Oxidizing power order: SiCl4 < SnCl4 < PbCl4 (B) Ionic character order: CsBr > RbBr > KBr > NaBr > LiBr (C) The ionic character of lead (II) halides decreases with increase in atomic no. of halogen (D) The oxidation state of Tl in Tl I3 is +3. 43. Statement-1: Hg22+ is good oxdising agent. Statement-2: 6s electrons are strongly attracted towards nucleus of Hg, due to poor shielding of 4f electrons. (A) Statement-1 is true, statement-2 is true and statement-2 is correct explanation for statement-1. (B) Statement-1 is true, statement-2 is true and statement-2 is NOT the correct explanation for statement-1 (C) Statement-1 is true, statement-2 is false. (D) Statement-1 is false, statement-2 is true. 44. Statement-1: SnCl4 doesn't exist and converts into SnCl2 and Cl2 spontaneously at room temperature. Statement-2: SnCl4 is more stable than SnCl2. (A) Statement-1 is true, statement-2 is true and statement-2 is correct explanation for statement-1. (B) Statement-1 is true, statement-2 is true and statement-2 is NOT the correct explanation for statement-1 (C) Statement-1 is true, statement-2 is false. (D) Statement-1 is false, statement-2 is true. Ionic compound: 45. Which of the following substance has the largest negative lattice energy? (A) NaCl (B) CaBr2 (C) NaBr (D) CaCl2 46. Choose the correct code for the following statements. I. The (–)ve value of H for the dissolution of ionic compound is enough to predict the compound is soluble in water at any temperature. II. For the alkali metals carbonate, solubility order decreases down the group. III. For the alkali metals ozonide, the thermal stability order increases down the group. IV. For the alkaline earth metals nitride, the thermal stability order increases down the group. (A) T T F F (B) T F F T (C) T F T F (D) F T T F 47. Out of the following which one has the highest values of covalent character? (A) ZnCl2 (B) CdCl2 (C) HgCl2 (D) CuCl 48. Compound having lowest Melting point. (A) BeCl2 (B) MgCl2 (C) CaCl2 (D) SrCl2 49. Which of the following order is correct of the given property. (A) LiCl > NaCl > KCl > RbCl > CsCl : Thermal stability order (B) BeF2 < MgF2 < CaF2 < SrF2 < BaF2 : solubility order 2– — 2+ + (C) NO > NO > NO = NO > NO : bond length order (D) BaO > SrO > CaO > BeO > MgO : basic character order PHYSICS WALLAH 16  CHEMICAL BONDING 50. Which of the following has highest covalent character. (A) CaCl2 (B) ZnCl2 (C) KCl (D) CuCl 51. Which of the following order is CORRECT: (A) BeF2 < BaF2 → Solubility 2 (B) BeO < BeF2 → Melting point (C) BeO < MgO → Acidic character (D) MgF2 < AlF3 → Covalent character 52. Which of the following order is CORRECT about thermal stability. (A) Li2CO3 < Cs2CO3 (B) BeCO3 < BaCO3 (C) LiNO3 < CsNO3 (D) All of these 53. Which of the following order is/are INCORRECT: (A) NaF < MgF2 < AlF3 (Lattice energy) (B) NaF < MgF2 < A l F3 (Melting point) (C) NaF < MgF2 < AlF3 (Polarizing power of cation) (D) NaF < MgF2 < AlF3 (% ionic character) 54. The correct solubility order is/are: (I) CaCO3 > SrCO3 > BaCO3 (II) Li2CO3 < Na2CO3 < K2CO3 (III) K2CO3 < Rb2CO3 < Cs2CO3 (IV) Na2CO3 > K2CO3 > Rb2CO3 (A) II, IV (B) I, IV (C) II, III, IV (D) I, II, III Molecular orbital theory: 55. Which of the following species have more number of electrons in bonding MO's as compared to antibonding MO's: (A) O2– (B) N2+ (C) C2 (D) All of these 56. Which of the following statement is INCORRECT: (A) KO2 is paramagnetic in nature (B) All halogens are coloured gases at room temperature (C) O2 is paramagnetic gas (D) Bond order of OF is 1.5 57. Assuming that if Hund's rule is violated, then the paramagnetic specie is: (A) B2 (B) O2 (C) NO (D) O2 58. Among the following species, which has the minimum bond length? (A) B2 (B) C2 (C) F2 (D) O2– 59. During change of O2 to O2– ion, the electron adds in which one of the following orbitals? (A) σ* 2pz orbital (B) σ 2pz orbital (C) π* 2px / π* 2py orbital (D) π 2px /π 2py orbital 60. The molecular orbital with highest energy in a nitrogen molecule is: (A) 2p (B) 2p (C) *2p (D) *2p PHYSICS WALLAH 17  CHEMICAL BONDING 61. According to Molecular orbital theory which of the following is correct? (A) LUMO level for C2 molecule is 2px orbital (B) In C2 molecules both the bonds are  bonds (C) In C22–ion there is one  and two  bonds (D) All the above are correct 62. N2 and O2 are converted to monocations N2+ and O2+ respectively, which is wrong statement: (A) In N2+, the N—N bond weakens (B) In O2+, the O—O bond order increases (C) In O2+, the paramagnetism decrease (D) N2+ becomes diamagnetic 63. Which of the following species absorb maximum energy in its HOMO-LUMO electronic transition? (A) O2 (B) N2– (C) C2 (D) N2 Miscellaneous: 64. Molecule in which central atom has sp3d2 hybridization is present. (A) IF7 (B) IO6–5 (C) XeF2 (D) XeO4 65. Which of the following oxyacid(s) has/have same hybridisation state for underlined atoms? (A) H2S2O8 (B) H2S2O7 (C) H2S2O2 (D) All of the above 66. Which of the following molecule/ion is planar and polar both: (A) NO3 (B) NO2 (C) PF5 (D) NH3 67. Choose the element which show maximum number of covalencies out of the given elements. (A) F (B) N (C) C (D) Cl 68. Which of the following order in correct against the property indicated: (A) PH4 < PCl4 < PBr4 (bond angle) (B) BF3 < NF3 < NH3 (dipole moment) (C) CCl4 < B(OH)3 < PCl5 (number of valence electrons used for bonding by central atom) (D) CH4 < CCl4 < CBr4 (order of bond polarity) 69. Which of the following have different shape from the others: (A) NOF3 (B) XeO4 (C) SOCl2 (D) BF4 70. Which of the following molecule/atom has lowest enthalpy of fusion? (A) H2 (B) He (C) Br2 (D) I2 71. Increasing order of stability of the +2 oxidation state of the ions? (A) Ca2+ < Ba2+ < Sr2+ (B) Pb2+ < Ge2+ < Sn2+ (C) Ge2+ < Sn2+ < Pb2+ (D) Cu2+ < Au2+ < Ag2+ 72. Two hybrid orbitals have a bond angle of 120º. The percentage of s-character in the hybrid orbital is nearly: (A) 25% (B) 33% (C) 50% (D) 66% PHYSICS WALLAH 18  CHEMICAL BONDING 73. Which of the following species has the same number of X–O–X linkage, where X = S or P? (I) S4O62– (II) S3O9 (III) S2O52– (IV) P3O92– (A) II & IV (B) II & III (C) I & III (D) I & IV Assertion-Reasoning type: In the following set of questions, a statement I is given and a corresponding statement II is given below it. Mark the correct answer as: (A) If both statement I and statement II are true and statement II is the correct explanation for statement I. (B) If both statement I and statement II are true but statement II is not the correct explanation for statement I. (C) If statement I is true but statement II is false. (D) If statement I is false but statement II is true. 74. Statement-I: XeH4 does not exist but XeF4 exists. Statement-II: F is more electronegative than H and causes lesser extent of d orbital contraction as compared to that by H atom. 75. Statement-I: (AlCl3)2 is not electron deficient [Al(CH3)3]2 is electron deficient. Statement-II: [(AlCl3)3]2 possesses 3c – 2e bond. 76. Statement-I: [AlBr4]– exists while the existence of [BBr4]– is questionable. Statement-II: Al is larger in size as compared to B atom. 77. Statement-I: dMn–O in MnO4– is less than that in MnO42– Statement-II: The higher oxidation state of an element causes higher extent of d orbital contraction and forms more effective  bond with O atoms PHYSICS WALLAH 19  CHEMICAL BONDING EXERCISE #2 Weak forces: 1. Which of the following option(s) is/are CORRECT? Type of interaction distance-energy function 1 1 (A) dipole-dipole  (B) H-bonding  r3 r3 1 1 (C) Ion-dipole  (D) London force  r2 r6 2. The correct order of the boiling point is/are: (A) He < Ne < Ar < Kr < Xe (B) H2 < He (C) H2 < D2 < T2 (D) BF3 < BMe3 Bent's and drago's rule: 3. Which of the following order is correct regarding %P character? (A) H2S has higher P character in S – H bond than the O – H bond in H2O (B) PH3 has higher P character in P – H bond than the N – H bond in NH3 (C) NH+4 has higher P character in N – H bond than the P–H bond in NH+4 (D) None of these 4. Which of the following statement(s) is/are CORRECT? (A) Axial bond length > equatorial bond length in PF5 (B) axial bond length (P –F) < equatorial bond length (P–Cl) in PF2Cl3 (C) All P–F bond lengths are equal in PF5 (D) axial bond length (P–F) > equatorial bond length (P–Cl) in PF2Cl3 5. Choose the correct angle order. (A) HPH in PH+4 = HCH in CH4 (B) HNH in NH3 < HPH in PH3 (C) HNH in NH3 < HPH in PH+4 (D) OSO in SO32− < ONO in NO3− 6. In which of the following back bonding is NOT possible: (A) N(CH3)3 (B) BO3–3 (C) P(CH3)3 (D) BF4– Back bonding: 7. Molecule(s) in which maximum number of atoms in a plane may be ten: (A) B2Me4H2 (B) Al2(CH3)6 (C) N(SiH3)3 (D) [Co(NH3)6]3+ 8. Which of the following statement(s) is/are CORRECT: (A) [B3O6]–3 ion is non-planar but B3N3H6 is planar (B) (H3Si)3N is planar but (SiH3)3P is pyramidal (C) H3C–N C S is bent but SiH3 - NCS is linear (D) (CH3)3N is pyramidal but (GeH3)3N is planar PHYSICS WALLAH 20  CHEMICAL BONDING 9. Which of the following statements is/are INCORRECT: (A) CHF3 is less acidic than CHCl3 (B) R3C–O–H is more acidic than R3Si–O–H (C) In BF3 back bonding is possible but in CO back bonding is not possible (D) PH3 is more basic than NH3 10. Select the correct order of bond angle. (A) O(SiH3)2 > OCl2 (B) N(SiH3)3 > N(CH3)3 (C) O(SiH3)2 < OCl2 (D) N(SiH3)3 < N(CH3)3 11. In which of the following compounds, underlined atom can change their hybridisation due to back bonding: (A) B3 N3H6 (B) N(SiH3 )3 (C) O(Si H3 )2 (D) H3 BO3 Multicentered bond: 12. No X–X bond exists in which of the following compounds having general form of X2H6? (A) B2H6 (B) C2H6 (C) Al2H6 (D) Si2H6 13. Which of the following molecules have CORRECT indicated overlapping. Molecule Overlapping in the bridge bond (if any) (A) Si2Cl6 sp3–p–sp3 (B) Be2H4 sp2–s–sp2 (C) Si2H6 sp3–s–sp3 (D) B2H6 sp3–s–sp3 Silicate: 14. In which of the following cases the number of corner shared per tetrahedron is '2': (A) Pyroxene chain silicate (B) Amphibole chain silicate (C) 5-membered cyclic silicate (D) None of these Odd electron species: 15. Select correct about NO2: (A) It is odd electron specie (B) N–O bond order = 1.5 (C) Paramagnetic specie (D) Isoelectronic with CO2 16. The number of specie(s) which are not perfectly planar. (A) C H 3 (B) C F3 (C) CHF2 (D) CHF2 17. Which of the following statement is CORRECT: (A) The free electron of ClO3 molecule is present in d-orbital of Cl-atom (B) The free electron of CF3 is present in sp3 hybrid orbital (C) NO is polar (D) The free electron of ClO2 molecule is present in d-orbital of Cl-atom PHYSICS WALLAH 21  CHEMICAL BONDING Hydrolysis: 18. Which of the following compounds do not give free halogen acid (Hydra acid) on hydrolysis with excess water as a final product? (A) NCl3 (B) PCl3 (C) SiCl4 (D) BF3 19. Select the CORRECT statement(s) re grading the hydrolysis of SF4: (A) In transition state H2O attacks from axial position (B) Six moles of NaOH are required for the complete neutralisation of hydrolysis product of one mole of compound (C) Oxidation state of 'S' in product is +6 (D) All the product(s) can form H-bonding 20. Which of the following compounds can form H3PO3 on hydrolysis: (A) P4O6 (B) P4O7 (C) P4O8 (D) P4O9 Molecule does not exist: 21. Which of the following species do not exist in nature. (A) PI5(TBP form) (B) PbI4 (C) HFO3 (D) ICl7 22. Which of the following do/does not exist? (A) SH6 (B) HFO4 (C) FeI3 (D) HClO3 Inert pair effect: 23. Which of the following have (18 + 2) electron configuration? (A) Pb2+ (B) Cd2+ (C) Bi3+ (D) SO42– 24. Which of following stability order is/are correct due to inert pair effect. (A) Hg > Hg2+ (B) Bi3+ < Bi5+ (C) Pb2+ > Pb4+ (D) Fe2+ < Fe3+ Ionic compound: 25. Which of the following order is/are CORRECT: (A) MgCO3 < BaCO3 (Thermal stability) (B) LiF < CsF (Solubility) (C) Li3N > K3N (Thermal stability) (D) MgSO3 > BaSO3 (Solubility) 26. Select the CORRECT order against the mentioned property: (A) NaNO3 < KNO3 < RbNO3 (Thermal stability) (B) NaF> KF > RbF (Covalent nature) (C) Si – O < P – O < S – O < C l – O (-bond strength) (D) F2 < Cl2 < Br2 < I2 (Bond length) 27. Correct order of solubility in water will be? (A) LiCl > NaCl > KCl < RbCl < CsCl (B) Li2CO3 < Na2CO3 < K2CO3 (C) LiF < NaF < KF < RbF (D) BeCO3 < MgCO3 < CaCO3 28. Which of the following will give metal oxide on heating? (A) CaCO3 (B) AgNO3 (C) K2CO3 (D) Li2CO3 PHYSICS WALLAH 22  CHEMICAL BONDING 29. Which of the following order is/are CORRECT: (A) NaCl < LiCl (m.p.) (B) CaF2 > CaO (lattice energy) (C) LiNO3 < NaNO3 (thermal stability) (D) Be3N2 > Ba3N2 (thermal stability) Molecular orbital theory: 30. Which of the following have identical bond order? (A) O22+ (B) NO+ (C) CN– (D) CN+ 31. Assuming that if Hund's rule is violated, then the diamagnetic specie(s) is/are: (A) B2 (B) O2 (C) NOƟ (D) O2 32. The paramagnetic molecule(s) which have non fractional bond order: (A) O2 (B) O2Ɵ (C) N22– (D) B2 Miscellaneous: 33. Bond angles which are associated with sp3d3 hybridization. (A) 90º (B) 120º (C) 180º (D) 72º 34. Which of following statement is/are CORRECT for ClOF3? (A) In hybridisation central atom uses its dxy orbital (B) In -bond formation central atom uses its 'p' orbital (C) The shape of molecule is see-saw (D) The molecule is non-planar 35. Which of the following species are planar as well as polar. (A) I3+ (B) NO2– (C) PCl3 (D) BO33– PHYSICS WALLAH 23  CHEMICAL BONDING EXERCISE #3 Integer type: 1. Which of the following pairs have dipole-dipole interaction? (BF3 + BF3), (CCl4 + Na+) (HCl + HCl), (CHCl3 + CHCl3), (K+ + HCl), (Na+ + Cl–) 2. Find the number of molecules in which axial orbital length is higher than equatorial orbital length of central atom: PCl5, PCl3F2, PF4Cl, PCl2F3, PF5 3. Find the total number of 2C – 2e– bond in Al2(C6H5)6 (excluding  bond) Fill your answer as sum of digits till you get the single digit answer. 4. Find the number of molecules, which do not have hybridisation, according to Drago's rule. PH3, SH2, AsH3, H2Se, SiH4 5. 6XeF4 + 12H2O → 4X + 2Y + 24HF + 3O2 In above reaction find the difference of oxidation state in central atom of X and Y. 6. Total number of molecules in which bridge bond formed by sp3–s–sp3 type overlap B2H6, Al2 (CH3)6, I2Cl6, Al2H6, Si2Cl6 7. Among the following total number of planar molecules/ions is. H3O+, I3, NO2Ɵ, ClF3, XeF2, ICl4, OCl2 8. For the given compounds, number of compounds which undergo complete hydrolysis in presence of excess amount of water in ordinary condition: SF4, XeF2, BiCl3, NF3, NCl3, POCl3, BF3 9. Find out the number (s) of molecule in which bond angle around under line atom is 120º: + H 3 BO3 , P(SiH3 )3 , N(SiH3 )3 , C H 3 , N(CH3 )3 , SnCl3− 10. Find the number of chemical species which undergoes hydrolysis through redox reaction. XeF2, XeF4, XeF6, SF4, PCl3, PCl5 11. Find the maximum number of F atom(s) in one plane in XeF5+: 12. Find the number of molecules which are polar PCl3F2, PCl2F3, P(CH3)3 (CF3)2, P(CH3)2 (CF3)3 13. Ratio of sp3 and sp2 hybridized atoms in the anionic part of Borax is_______ (If ans is 12 : 4 then represented as 124 and fill your answer as sum of digits (excluding decimal places) till you get the single digit) 14. Number of species having bond order 2 will be? O2+2, N2+2, N2–2, O2+, N2+, C2, B2–2 15. Find the total number of 2C – 2e– bond in Al2 (C6H5)6 (excluding  bond) Fill your answer as sum of digits till you get the single digit answer. PHYSICS WALLAH 24  CHEMICAL BONDING EXERCISE #4 Paragraph for Question 1 to 2: Bent's rule can be stated as follows. "The central atom projects the hybrid orbitals of less s-character" towards more electronegative atom. 1. Which of the following statement is CORRECT? (A) CH3F is not perfect tetrahedral (B) PCl3F2 has got a trigonal bipyramidal (T.B.P) shape. (C) In PCl3F2, the two fluorine atoms preferably are positioned in the axial directions. (D) All are correct 2. Which of the following order is CORRECT? (A) dC–H in CH3Cl > dC–H in CH3F (B) dC–H in CH3Cl < dC–H in CH3F (C) HPH (PH3) > HPH (PH4+) (D) H– Ĉ –H in CH4 > F– Ĉ –F in CF4 Paragraph for Question 3 to 4: Back bonding is a type of sideways overlapping. 3. Which of the following molecule has 2p – 3d back bonding. (A) PCl3 (B) CCl3– (C) BCl3 (D) (BO2–)3 4. Which of the following has CORRECT order of strength of back bonding. (A) BF3 > BCl3 (B) O(SiH3)2 > S(SiH3)2 (C) N(SiH3)3 < NH2SiH3 (D) All are correct Paragraph for Question 5 to 6: Qualitatively, the formation of molecular orbitals can be understood in terms of the constructive or destructive interference of the electron waves of the combining atoms. In the formation of bonding molecular orbital, the two electron waves of the bonding atoms reinforce each other due to constructive interference while in the formation of antibonding molecular orbital, the electron waves cancel each other due to destructive interference. 5. Which of the following combinations give(s) antibonding sigma molecular orbital if z-axis is the internuclear axis? (A) (B) (C) (D) 6. Which of the following specie does not exist: (A) HeH+ (B) Be2 (C) C22– (D) NO+ Paragraph for Question 7 to 8: According to Bent's Rule, which states: more electronegative substituents prefer hybrid orbitals having less s-character and more electropositive substituents prefer hybrid orbitals having more s-character 7. Among the following, which has/have equatorial bonds becomes stronger and shorter than the axial bonds? (A) PCl5 (B) ClF3 (C) SF4 (D) All of these PHYSICS WALLAH 25  CHEMICAL BONDING 8. Which of the following has CORRECT order of their indicating properties? (A) F– Ĉ –F(CH2F2) > 4– Ĉ –H(CH4); bond angle (B) PH3 < PF3; bond angle (C) POF3 < POCl3; P – O bond strength (D) All of these Paragraph for Question 9 to 10: When a substance undergoes nucleopilic substitution reaction and the nucleophile is solvent itself, then the reaction is known as solvolysis, if the solvent used is water then the reaction is called as hydrolysis. 9. The product(s) of hydrolysis of NCl3 is/are: (A) HNO2 (B) HCl (C) NH3 (D) HOCl 10. Which of the following compounds on hydrolysis produce oxyacid having basicity three in water: (A) PCl5 (B) AsCl3 (C) PCl3 (D) BCl3 Paragraph for Question 11 to 12: Molecular orbital theory is based on linear combination of atomic orbitals (LCAO). According to LCAO when respective atomic orbitals of the atoms interact, they undergoes constructive and destructive interference giving two types of molecular orbital i.e. bonding and antibonding molecular orbitals respectively. 11. Which of the following overlapping result ungerade molecular orbital. (A) (B) (C) (D) 12. Which of the following property does not change when O2 is converted to O2–: (A) Magnetic behaviour (B) Magnetic moment (C) Bond order (D) Number of bonding electron Paragraph for Question Nos. 13 to 15: Bridge bonding is a specific kind of bonding in pages of chemistry. In general σ-bond pair delocalisation is very difficult. But electron deficiency of the central atom forces to delocalise and forms this kind of bond. 13. The state of hybridisation of central atom in dimer form of both BH3 and BeH2 is: (A) sp2, sp (B) sp3, sp2 (C) sp3, sp3 (D) sp2, sp3 14. Which of the following molecule has complete octet: (A) B2H6 (B) Al2Cl6 (C) Be2Cl4 (D) BeH2 15. Which of the following is/are electron deficient compounds? (A) NaBH4 (B) B2H6 (C) Al2Cl6 (D) BeCl2(s) PHYSICS WALLAH 26  CHEMICAL BONDING Matching list: 16. List I List II (Species) (Bond order) (P) O2– (1) 2.5 (Q) N2+ (2) 1.0 (R) H2+ (3) 1.5 (S) B2 (4) 0.5 Code: (P) (Q) (R) (S) (A) 2 3 4 1 (B) 3 1 4 2 (C) 3 1 2 4 (D) 4 1 2 3 17. List I List II (Unit of silicate) (Number of shared oxygen atom per tetrahedral unit) (P) Si2O7–6 (1) 3 (Q) (Si2O5.5–3)n (2) 1 (R) SiO2 (3) 2.5 (avg.) (S) (Si2O52–) (4) 4 Code: (P) (Q) (R) (S) (A) 2 3 4 1 (B) 3 1 2 4 (C) 2 3 1 4 (D) 4 2 3 1 18. Match column-I with column-II: List I List II (P) BF3 (1) Exist in dimeric form (Q) AlCl3 (2) Effective back bond is present (R) SiO2 (3) Acts as lewis acid (S) CO (4) Exist in polymeric form Select correct code of your answer: Code : (P) (Q) (R) (S) (A) 3 2 4 1 (B) 1 2 4 3 (C) 3 1 4 2 (D) 1 2 3 4 Matrix match: 19. Column-I Column-II (A) BF3 (P) Intra molecular lewis acid-base interaction (B) BCl3 (Q) 2p – 3p back bond (C) H3BO3 (R) Lewis acid (D) B(OCH3)3 (S) Incomplete octet of central atom boron (T) sp2 hybridisation of B 20. Column-I Column-II (Cumulative interaction) (A) HCl and HCl (P) dipole - dipole (B) HCl and C6H6 (Q) Ion-dipole + (C) Na and NH3 (R) Ion-induced dipole - dipole (D) K+ and CCl4 (S) induced dipole (T) London dispersion force PHYSICS WALLAH 27  CHEMICAL BONDING EXERCISE #5 (JEE MAIN) 1. The bond order in NO is 2.5 while that in NO+ is 3. Which of the following statement is true for these two species? [AIEEE–2004] + (A) Bond length in NO is equal to that NO (B) Bond length in NO is greater than NO+ (C) Bond length in NO+ is greater than NO (D) Bond length is unpredictable 2. The states of hybridization of boron and oxygen atoms in boric acid (H3BO3) are respectively: [AIEEE 2004] 3 2 2 3 2 2 (A) sp and sp (B) sp and sp (C) sp and sp (D) sp and sp3 3 3. The maximum number of 90º angles between bond pair-bond pair of electrons is observed in: [AIEEE 2004] 2 3 3 3 2 (A) dsp hybridization (B) sp d hybridization (C) dsp hybridization (D) sp d hybridization 4. Which one of the following specie is diamagnetic in nature? [AIEEE-2005] – (A) He2+ (B) H2 (C) H2+ (D) H2 5. Which of the following molecule\ion does not contain unpaired electrons? [AIEEE-2006] + 2– (A) N2 (B) O2 (C) O2 (D) B2 6. Among the following mixtures, dipole-dipole as the major interaction, is present in: [AIEEE-2006] (A) KCl and water (B) benzene and carbon tetrachloride (C) benzene and ethanol (D) acetonitrile and acetone 7. A metal, M forms chlorides in its +2 and +4 oxidation states. Which of the following statement about these chlorides is correct? [AIEEE-2006] (A) MCl2 is more ionic than MCl4 (B) MCl2 is more easily hydrolysed than MCl4 (C) MCl2 is more volatile than MCl4 (D) MCl2 is more soluble in anhydrous ethanol than MCl4 8. The decreasing values of bond angles from NH3 (106º) to SbH3 (91º) down group-15 of the periodic table is due to: [AIEEE-2006] (A) decreasing lp – bp repulsion (B) increasing electronegativity (C) increasing bp – bp repulsion (D) increasing p-orbital character in sp3 9. In which of the following ionization process, the bond order has increased and the magnetic behaviour has changed: [AIEEE-2007] (A) NO → NO + (B) O2 → O2 + (C) N2 → N2 + (D) C2 → C2+ 10. Which of the following species exhibits the diamagnetic behaviour: [AIEEE-2007] (A) O2+ (B) O2 (C) NO (D) O2 2– 11. Which one of the following pairs of species have the same bond order? [AIEEE-2008] (A) CN– and NO+ (B) CN– and CN+ (C) O2– and CN– (D) NO+ and CN+ PHYSICS WALLAH 28  CHEMICAL BONDING 12. The bond dissociation energy of B–F in BF3 is 646 kJ mol–1 whereas that of C–F in CF4 is 515 kJ mol–1. The correct reason for higher B–F bond dissociation energy as compared to that of C–F is: [AIEEE-2009] (A) Significant p – p interaction between B and F in BF3 whereas there is not possibility of such interaction between C and F in CF4. (B) Lower degree of p – p interaction between B and F in BF3 than that between C and F in CF4 (C) Smaller size of B-atom as compared to that of C-atom (D) Stronger  bond between B and F in BF3 as compared to that between C and F in CF4 13. Using MO theory predict which of the following species has the shortest bond length? [AIEEE-2009] – 2– 2+ + (A) O2 (B) O2 (C) O2 (D) O2 14. Among the following the maximum covalent character is shown by the compound: [AIEEE-2011] (A) AlCl3 (B) MgCl2 (C) FeCl2 (D) SnCl2 15. Which one of the following molecules is expected to exhibit diamagnetic behaviour? [AIEEE-2013] (A) C2 (B) N2 (C) O2 (D) S2 16. In which of the following pairs of molecules/ions, both the species are not likely to exist? [JEE-M-2013] + 2– – 2– 2+ – (A) H2 , He2 (B) H2 , He2 (C) H2 , He (D) H2 , He22+ 17. Stability of the species Li2, Li2– and 2 Li2+ increases in the order of: [JEE-M-2013] + – – + – – (A) Li2 < Li2 < Li2 (B) Li2 < Li2 < Li2 (C) Li2 < Li2 < 2 Li2 (D) Li2 < Li2 < Li2+ + 18. Which one of the following properties is not shown by NO? [JEE-M-2014] (A) It combines with oxygen to form nitrogen dioxide (B) It's bond order is 2.5 (C) It is diamagnetic in gaseous state (D) It is a neutral oxide 19. The correct order of thermal stability of hydroxides is: [JEE-M-2015 (on line)] (A) Ba(OH)2 < Sr(OH)2 < Ca(OH)2 < Mg(OH)2 (B) Mg(OH)2 < Sr(OH)2 < Ca(OH)2 < Ba(OH)2 (C) Mg(OH)2 < Ca(OH)2 < Sr(OH)2 < Ba(OH)2 (D) Ba(OH)2 < Ca(OH)2 < Sr(OH)2 < Mg(OH)2 20. Which of the alkaline earth metal halides given below is essentially covalent in nature: [JEE-M-2015 (on line)] (A) SrCl2 (B) CaCl2 (C) BeCl2 (D) MgCl2 21. Which one of the following alkaline earth metal sulphates has its hydration enthalpy greater than its lattice enthalpy? [JEE-M-2015] (A) BaSO4 (B) SrSO4 (C) CaSO4 (D) BeSO4 PHYSICS WALLAH 29  CHEMICAL BONDING 22. The intermolecular interaction that is dependent on the inverse cube of distance between the molecules is: [JEE-M-2015] (A) London force (B) Hydrogen bond (C) ion-ion interaction (D) ion-dipole interaction 23. Which one has the highest boiling point? [JEE-M-2015] (A) Kr (B) Xe (C) He (D) Ne 24. Which intermolecular force is most responsible in allowing xenon gas to liquefy? [JEE (MAIN) ONLINE 2016] (A) Ionic (B) Instantaneous dipole- induced dipole (C) Dipole - dipole (D) Ion - dipole 25. The bond angle H–X–H is the greatest in the compound: [JEE (MAIN) ONLINE 2016] (A) NH3 (B) H2O (C) PH3 (D) CH4 26. Which of the following species is not paramagnetic? [JEE (MAIN) ONLINE 2017] (A) NO (B) CO (C) O2 (D) B2 27. Which of the following is paramagnetic? [JEE-MAIN-2017 (ONLINE)] (A) CO (B) O22– (C) NO+ (D) B2 28. sp3d2 hybridization is not displayed by: [JEE-MAIN-2017 (On-line)] (A) [CrF6]3– (B) BrF5 (C) PF5 (D) SF6 29. The number of S=O and S–OH bonds present in peroxodisulphuric acid and pyrosulphuric acid respectively are: [JEE-MAIN-2017 (On-line)] (A) (2 and 4) and (2 and 4) (B) (4 and 2) and (2 and 4) (C) (2 and 2) and (2 and 2) (D) (4 and 2) and (4 and 2) 30. The correct sequence of decreasing number of -bonds in the structures of H2SO3, H2SO4 and H2S2O7 is: [JEE-MAIN-2017 (On-line)] (A) H2S2O7 > H2SO4 > H2SO3 (B) H2SO3 > H2SO4 > H2S2O7 (C) H2S2O7 > H2SO3 > H2SO4 (D) H2SO4 > H2S2O7 > H2SO3 31. The increasing order of the boiling point for the following compounds is: [JEE-MAIN-2017 (On-line)] (I) C2H5OH (II) C2H5Cl (III) C2H5CH3 (IV) C2H5OCH3 (A) (III) < (II) < (I) < (IV) (B) (II) < (III) < (IV) < (I) (C) (IV) < (III) < (I) < (II) (D) (III) < (IV) < (II) < (I) 32. The number of P–OH bonds and the oxidation state of phosphorus atom in pyrophosphoric acid (H4P2O7) respectively are: [JEE-MAIN-2017 (On-line)] (A) five and four (B) five and five (C) four and five (D) four and four PHYSICS WALLAH 30  CHEMICAL BONDING 33. The group having triangular planar structures is: [JEE-MAIN-2017 (On-line)] (A) CO32–, NO3–, SO3 (B) NCl3, BCl3, SO3 (C) NH3, SO3, CO32– (D) BF3, NF3, CO32– 34. In the molecular orbital diagram for the molecular ion, N2+, the number of electrons in the 2p molecular orbitals: [JEE Main online - 2018] (A) 0 (B) 1 (C) 2 (D) 3 35. Which of following is a Lewis acid? [JEE Main online - 2018] (A) PH3 (B) B(CH3)3 (C) NaH (D) NF3 36. (I) (II) [JEE Main online - 2018] H—N---N---N In hydrogen azide (above) the bond orders of bonds (I) and (II) are: (I) (II) (A) 2 (B) >2 2 >2 (D) PF3 > BF3 (B) I3 > BF3 > NH3 > PF3 – (C) BF3 > I3 > PF3 > NH3 (D) BF3 > NH3 > PF3 > I3– 38. Xenon hexafluoride on partial hydrolysis produces compounds ‘X’ and ‘Y’. Compounds ’X’ and ‘Y’ and the oxidation state of Xe are respectively: [JEE Main online - 2018] (A) XeO2(+4) and XeO3(+6 (B) XeOF4(+6) AND XeO3(+6) (C) XeO2F2(+6) and XeO2(+4) (D) XeOF4(+6) and XeO2F2(+6) 39. Among the oxides of nitrogen: N2O3, N2O4 and N2O5; the molecule(s) having nitrogen-nitrogen bond is/are: [JEE Main online - 2018] (A) Only N2O5 (B) N2O3 and N2O5 (C) N2O5 and N2O5 (D) N2O3 and N2O4 40. Which of the following conversions involves change in both shape and hybridisation? [JEE Main online - 2018] (A) NH3 → NH4 + (B) CH4 → C2H6 (C) H2O → H3O + (D) BF3 → BF4– 41. A group 13 element ‘X’ reacts with chlorine gas to produce a compound XCl 3 is electron deficient and easily reacts with NH3 to form Cl3X  NH3 adduct; however, XCl3 does not dimerize. X is: [JEE Main online - 2018] (A) B (B) Al (C) Ga (D) In 42. Which of the following best describes the diagram below of a molecular orbital? [JEE Main online - 2018] (A) A non-bonding orbital (B) An antibonding  orbital (C) A bonding  orbital (D) An antibonding  orbital PHYSICS WALLAH 31  CHEMICAL BONDING 43. In KO2, the nature of oxygen species and the oxidation state of oxygen atom are, respectively: [JEE Main online - 2018] (A) Oxide an –2 (B) superoxide and –1/2 (C) Peroxide and –1/2 (D) Superoxide and –1 44. The number of P–O bonds in P4O6 is: [JEE Main online - 2018] (A) 6 (B) 9 (C) 12 (D) 18 45. In XeO3F2, the number of -bond(s), -bond(s) and lone pair(s) on Xe atom respectively are: [JEE Main online - 2018] (A) 5, 2, 0 (B) 4, 2, 2 (C) 5, 3, 0 (D) 4, 4, 0 46. Identify the pair in which the geometry of the species is T-shpes and square pyramidal, respectively: [JEE Main online - 2018] – – (A) CIF3 and IO4 (B) ICl2 and ICI5 (C) XeOF2 and XeOF4 (D) IO3– and IO2F2– 47. The incorrect geometry is represented by: [JEE Main online - 2018] (A) BF3 - trigonal planar (B) H2O - bent (C) NF3 - trigonal planar (D) AsF5 = trigonal bipyramidal 48. Correct statements among a to d regarding silicones are: [JEE Main online - 2019] (a) They are polymers with hydrophobic character (b) They are biocompatible. (c) In general, they have high thermal stability and low dielectric strength. (d) Usually, they are resistant to oxidation and used as greases. (A) (a), (b) and (c) only (B) (a), and (b) only (C) (a), (b), (c) and (d) (D) (a), (b) and (d) only 49. According to molecular orbital theory, which of the following is true with respect to Li2+ and Li2–? [JEE Main online - 2019] (A) Both are unstable (B) Li2 is unstable and Li2– is stable + (C) Li2+ is stable and Li2– is unstable (D) Both are stable 50. The one that is extensively used as a piezoelectric material is: [JEE Main online - 2019] (A) Quartz (B) Amorphous silica (C) Mica (D) Tridymite 51. Aluminium is usually found in +3 oxidation state. In contrast, thallium exists in +1 and +3 oxidation states. This is due to: [JEE Main online - 2019] (A) lanthanoid contraction (B) lattice effect (C) diagonal relationship (D) inert pair effect 52. In which of the following processes, the bond order has increased and paramagnetic character has changed to diamagnetic? [JEE Main online - 2019] (A) O2 ⎯→ O22– (B) O2 ⎯→ O2+ (C) NO ⎯→ NO+ (D) N2 ⎯→ N2+ PHYSICS WALLAH 32  CHEMICAL BONDING 53. The type of hybridisation and number of lone pair(s) of electrons of Xe in XeOF4 respectively, are: [JEE Main online - 2019] 3 3 2 3 (A) sp d and 2 (B) sp d and 2 (C) sp d and 1 (D) sp3d2 and 1 54. Two pi and half sigma bonds are present in: [JEE Main online - 2019] (A) N2+ (B) N2 (C) O2 + (D) O2 55. The number of 2-centre-2-electron and 3-centre-2-electron bonds in B2H6, respectively, are: [JEE Main online - 2019] (A) 2 and 2 (B) 4 and 2 (C) 2 and 4 (D) 2 and 1 56. The chloride that cannot get hydrolysed is: [JEE Main online - 2019] (A) SiCl4 (B) CCl4 (C) PbCl4 (D) SnCl4 57. The relative stability of +1 oxidation state of group 13 elements follows the order: [JEE Main online - 2019] (A) Ga < Al < In < Tl (B) Al < Ga < In < Tl (C) Al < Ga < Tl < In (D) Tl < In < Ga < Al 58. The hydride that is NOT electron deficient is: [JEE Main online - 2019] (A) SiH4 (B) AlH3 (C) B2H6 (D) GaH3 The shape/structure of  XeF5  and XeO3 F2 , respectively, are: − 59. [JEE Main online - 2020] (A) Pentagonal planar and trigonal bipyramidal (B) Trigonal bipyramidal and pentagonal planar (C) Octahedral and square pyramidal (D) Trigonal bipyramidal and trigonal bipyramidal 60. If AB4 molecule is a polar molecule, a possible geometry of AB4 is: [JEE Main online - 2020] (A) Tetrahedral (B) See-saw (C) Rectangular planar (D) Square planar 61. The number of sp2 hybrid orbitals in a molecule of benzene is: [JEE Main online - 2020] (A) 24 (B) 12 (C) 6 (D) 18 62. If the magnetic moment of a dioxygen species is 1.73 B.M, it may be: [JEE Main online - 2020] (A) O−2 or O2+ (B) O2 ,O2− or O+2 (C) O 2 or O+2 (D) O 2 or O−2 63. Arrange the following bonds according to their average bond energies in descending order: [JEE Main online - 2020] C–Cl, C–Br, C–F, C–I (A) C–Br > C–I > C–Cl > C–F (B) C–Cl > C–Br > C–I > C–F (C) C–I > C–Br > C–Cl > C–F (D) C–F > C–Cl > C–Br > C–I 64. The bond order and the magnetic characteristics of CN– are: [JEE Main online - 2020] 1 1 (A) 3, paramagnetic (B) 2 , paramagnetic (C) 3, diamagnetic (D) 2 , diamagnetic 2 2 PHYSICS WALLAH 33  CHEMICAL BONDING 65. The relative strength of interionic/intermolecular forces in decreasing order is: [JEE Main online - 2020] (A) dipole-dipole > ion-dipole > ion-ion (B) ion-dipole > dipole-dipole > ion-ion (C) ion-dipole > ion-ion > dipole-dipole (D) ion-ion > ion-dipole > dipole-dipole 66. The dipole of CCl4, CHCl3 and CH4 are in the order: [JEE Main online - 2020] (A) CCl4 < CH4 < CHCl3 (B) CH4 = CCl4 < CHCl3 (C) CH4 < CCl4 < CHCl3 (D) CHCl3 < CH4 = CCl4 67. The increasing order of boiling points of the following compounds is: [JEE Main online - 2020] (A) I < III < IV < II (B) I < IV< II < III (C) IV < I < II < III (D) III < I < II < IV 68. The compound that has the largest H–M–H bond angle (M = N, O, S, C) is: [JEE Main online - 2020] (A) H2O (B) NH3 (C) H2S (D) CH4 69. The potential energy curve for the H2 molecule as a function of internuclear distance is: [JEE Main online - 2020] (A) (B) (C) (D) 70. The reaction in which the hybridisation of the underlined atom is affected is: [JEE Main online - 2020] (A) H3PO2 ⎯⎯⎯⎯⎯⎯ Disproportionation → (B) H2SO4 + NaCl ⎯⎯⎯ 420K → + (C) NH3 ⎯⎯→ H (D) XeF4 + SbF5 ⎯⎯ → 71. If the boiling point of H2O is 373 K and the boiling point of H2S will be: [JEE Main online - 2020] (A) less than 300 K (B) equal to 373 K (C) more than 373 K (D) greater than 300 K but less than 373 K PHYSICS WALLAH 34  CHEMICAL BONDING 72. Of the species, NO, NO+, NO2+ and NO– the one with minimum bond strength is: [JEE Main online - 2020] (A) NO + (B) NO (C) NO 2+ (D) NO– 73. Match the type of interaction in column A with the distance dependence of their interaction energy in column B: [JEE Main online - 2020] A B 1 (i) ion-ion (a) r 1 (ii) Dipole-dipole (b) 2 r 1 (iii) London dispersion (c) 3 r 1 (d) 6 r (A) (i)-(b); (ii)-(d); (iii)-(c) (B) (i)-(a); (ii)-(b); (iii)-(d) (C) (i)-(a); (ii)-(b); (iii)-(c) (D) (i)-(a); (ii)-(c); (iii)-(d) 74. The molecular geometry of SF6 is octahedral. What is the geometry of SF4 (including lone pair(s) of electrons, if (any)? [JEE Main online - 2020] (A) Tetrahedral (B) Trigonal bipyramidal (C) Pyramidal (D) Square planar 75. Among the compounds A and B with molecular formula C9H18O3, A is having higher boiling point than B. The possible structures of A and B are: [JEE Main online - 2020] (A) (B) (C) (D) 76. The predominant intermolecular forces present in ethyl acetate, a liquid are: [JEE Main online - 2020] (A) London dispersion and dipole-dipole (B) Hydrogen bonding and London dispersion (C) Dipole-dipole and hydrogen bonding (D) London dispersion, dipole-dipole and hydrogen bonding PHYSICS WALLAH 35