CONTECH 24 Past Paper PDF

# ACT-Concept Test in Chemistry (CONTECH) ## February 2024 **Time:** 2 hrs **Full Marks:** 80 ## Answer All Questions **Q1.** The defect that has the presence of cation in the interstitial site is * (A) Schottky defect * (B) Frenkel defect * (C) Metal deficiency defect * (D) Valency defect **Q2.** Conc HNO3 is added before proceeding to test group III cations to * (A) oxidize any remaining H2S. * (B) convert ferrous ion into ferric ion. * (C) form nitrates which give granular ppt * (D) increase ionisation of ammonium hydroxide **Q3.** The strongest O-O bond exists in * (A) O2+ * (B) O2 * (C) O22- * (D) O2- **Q4.** The angle through which plane of plane polarized light (PPL) is rotated is measured by * (A) Polarimeter * (B) Optical meter * (C) Stereo meter * (D) Chirality meter **Q5.** The stability of lyophobic colloid is a consequence of * (A) electrical double layer at the surface of the particle * (B) van der waals forces between the particles * (C) small particle size * (D) shape of the particle **Q 6.** The principle not covered under Green Chemistry Principles is * (A) cleaning up the waste is welcomed. * (B) unnecessary derivatization should be avoided. * (C) catalytic reagents are superior to stoichiometric reagents. * (D) a raw material of feedstock should be renewable rather than depleting wherever practicable. **Q7.** The least economical reaction is * (A) Addition reaction * (C) Substitution reaction * (B) Elimination reaction * (D) Rearrangement reaction **Q8.** The most important green solvent is * (A) Liquid nitrogen * (C) Glycol * (B) Supercritical CO2 * (D) Water **Q9.** The number of sustainable development goals covered in 'the 2030 Agenda for sustainable Development' accepted by United Nations Members in 2015 is * (A) 5 * (B) 17 * (C) 19 * (D) 21 **Q 10.** Rusting does not occur with stainless steel because * (A) Iron gets combined with chromium and nickel. * (B) Iron gets protected with the layer of chromium oxide layer. * (C) Nickel present in it prevents rusting. * (D) Iron forms a strong chemical bond with rest of the components in stainless steel. **Q11.** Number of carbon-carbon and carbon-nitrogen bonds in hexamethylenetetramine is * (A) Zero and 10 * (B) 10 and Zero * (C) Zero and 12. * (D) 12 and zero **Q12.** The molecule that violates the VSEPR (Valence Shell Electron Pair Repulsion) theory by exhibiting a molecular geometry different from what is predicted based on the number of electron domains is * (A) SF4 (Sulfur tetrafluoride) * (C) NH3 (Ammonia) * (B) PCl3 (Phosphorus trichloride) * (D) IF5 (Iodine pentafluoride) **Q 13.** Anisole is more reactive than toluene as the -OCH3 group * (A) is an electron donating group * (C) exhibits mesomeric effect. * (B) is an electron withdrawing group. * (D) A & C both. **Q14.** In accordance with the 1st law of thermodynamics the correct statement is * (A) In an adiabatic process, AU = -w * (B) In an isothermal process, q = +w * (C) In an isochoric process, AU = -q * (D) In a cyclic process, q = -w **Q 15.** 5g of a substance is dissolved in 150g benzene. If the molality of the substance is close to 0.55mol kg-1 then its molar mass is close to : * (A) 40 * (B) 50 * (C) 60 * (D) 7 **Q 16.** A colloid formed by dispersion of a gas in a liquid is * (A) cloud * (B) mist * (C) soap foam * (D) fog **Q 17.** An example of calcinations is * (A) 2Cu2O + CuS 6 Cu + SO2 * (B) FeO + C→ Fe + CO * (C) 2 Cu2S + 3O2 2Cu2O + 2 SO2 * (D) CaCO3. MgCO CaO + MgO + 2 CO2 **Q 18.** The set of compounds showing increasing oxidation state of metals is * (A) CrO, V2O5, MnO2, Ti2O3 * (C) Cu2O, CrO2, V2O5, CrO3 * (B) CuO, MnO2, CrO3, V2O5 * (D) ZnO, MnO2, CrO3, Fe2O3 **Q 19.** The correct option for the species used to bombard with the sample in mass spectroscopy is * (A) electrons * (B) protons * (C) neutrons * (D) alpha particles **Q 20.** The method that doesn't come under the chemical methods of quantitative analysis is * (A) Volumetric * (B) Gravimetric * (C) Titrimetric * (D) Magnetic Susceptibility **Q21.** The ion containing maximum number of unpaired electrons is * (A) Fe2+ * (B) Fe3+ * (C) Co2+ * (D) Co3+ **Q22.** The respective Oxidation number and Coordination number of Cobalt in [Co(NH3)4(H2O)(Br)](NO3)2 are * (A) +3 and 4 * (B) +3 and 6 * (C) +2 and 4 * (D) +2 and 5 **Q 23.** Polystyrene can be classified as : * (A) addition polymer or thermoplastic polymer. * (B) co-polymer or fibers. * (C) condensation polymer or fibers. * (D) condensation polymer or thermosetting polymer. **Q 24.** 11g carbon dioxide gas may be obtained by combustion of x mole of methane. The value of x is * (A) 0.11 * (B) 0.22 * (C) 0.25 * (D) 0.50 **Q 25.** In the equation, 2 KCIO3 (s)→ 2 KCl (s) + 3O2 (g) the set showing lowest and highest oxidation states, respectively, is * (A) K in KCl and K in KCIO3 * (C) O in KCIO3 and Cl in KCIO3 * (B) O in KCIO3 and O in O2 * (D) Cl in KCIO3 and Cl in KCl **Q 26.** The statement that is not true about NH3 and NF3 is * (A) Dipole moment of NH3 is less than that of NF3. * (B) Nitrogen atoms of both the molecules sp3 hybridized. * (C) Both are pyramidal in shape. * (D) NF3 bond angle is 102° whereas in NH3 107°. **Q 27.** The metal ion that plays an important role in muscle contraction is * (A) K+ * (B) Na+ * (C) Mg2+ * (D) Ca2+ **Q 28.** In the borax bead test of copper using copper sulphate and borax, the reason that holds true to get the bluish-green product is * (A) Na2B4O7.10H2O and copper sulphate. * (B) Copper sulphate and sodium metaborate. * (C) Boric anhydride and copper oxide. * (D) Copper oxide and Na2B4O7. **Q 29.** The ratio of 10 milligram and 5 nanogram of a substance is * (A) 1: 5x10-3 * (B) 2: 1x103 * (C) 1x103: 2 * (D) 2x103: 1 **Q 30.** An element X with its outermost orbital 2p2 forms two compounds with another element Y having 2p1 as the outermost orbital. The number of atoms of element Y per molecule in these compounds are * (A) 1 and 2 * (B) 1 and 3 * (C) 2 and 3 * (D) 1 and 4 **Q 31.** Debye forces involve * (A) Temporary dipole-induced dipole interactions. * (C) Dipole-induced dipole interactions. * (B) Dipole-Dipole interactions. * (D) Hydrogen bonding. **Q 32.** The set of salts placed in increasing order of their lattice energies is * (A) KCl, LiF, Cal2, BeBr2 * (C) BeBr2, Cal2, LiF, KCI * (B) LiF, KCl, Cal2, BeBr2 * (D) Cal2, BeBr2, KCI, LiF **Q 33.** The incorrect functional group of organic compound is * (A) Isocyano * (C) Isocyanide * (B) Carbonyl * (D) Carboxyl **Q 34.** The set of molecules having trigonal bipyramidal geometry is * (A) XeO3 and [XeF3]+ * (C) XeO3F2 and [XeF5]+ * (B) XeO4 and XeO2F2 * (D) XeF2 and XeOF2 **Q35.** The set of oxides that are placed in the order - weak base, amphoteric, weak acid and strong acid is * (A) In2O3, SiO2, N2O5, SO3 * (C) P4O10, PbO2, Sb2O5, N2O5 * (B) Ti2O3, Al2O3, B2O3, SO3 * (D) B2O3, Al2O3, N2O5, P4O10 **Q 36.** The order of the hybridization of carbon atoms from left to right in the molecule CH3-CH=C=CH2, is * (A) sp3, sp2, sp, sp3 * (C) sp3, sp, sp, sp2 * (B) sp3, sp2, sp, sp2 * (D) sp2, sp2, sp, sp3 **Q 37.** An alkyl halide (X) reacts with sodium to form 4, 5 - diethyloctane. The compound X is * (A) CH3(CH2)3F * (C) CH3(CH2)2CHICH3 * (B) CH3(CH2)3Br * (D) CH3(CH2)2CHBrCH2CH3 **Q 38** In the ideal gas equation, the SI unit for the gas constant is * (A) mol-1 K-1 * (C) L atom K-1 mol-1 * (B) bar L mol-1 K-1 * (D) erg mol-1 K-1 **Q 39.** The property that is shown by both, the crystalline solid and the liquid crystals is * (A) Fluidity * (C) Viscosity * (B) Surface tension * (D) Anisotropy **Q 40.** The set of liquids that represents completely miscible liquids is * (A) benzene and ethanol * (C) phenol and water * (B) benzene and toluene * (D) aniline hexane **Q 41.** A compound X on treatment with zinc amalgam and hydrochloric acid forms the compound Y. Compound Y on heating with bromine at 127°C gives mainly 2-bromopropane. Compound X and Y respectively are * (A) propanone and propene * (C) acetone and propene * (B) acetone and propane * (D) acetaldehyde and propane **Q 42.** Ethene reacts with formaldehyde in presence of dilute HCl, first forms a compound X and then gives 1, 3 - dioxane. The compound X is: * (A) Propanol * (C) propane 1,3-diol * (B) propane 1,2-diol * (D) propanal **Q 43.** A compound X reacts with zinc in the presence of Nal and Na2CO3 to form cyclobutane and zinc dibromide. The compound X is : * (A) 1,4-dibromobutane * (C) 1,1-dibromobutane * (B) ethylbromide * (D) butylbromide **Q 44.** The reason of having diagonal relationship between Be and Al is * (A) Similar ionic radii * (C) Similar atomic radii * (B) Similar charge/radius ratio * (D) Similar ionisation enthalpy **Q 45.** Methanol and ethanol can be distinguished by using * (A) Schiff's reagent * (C) Sodium hydroxide and Iodine * (B) Fehling Solution * (D) Phthalein fusion test **Q 46.** The conjugate base of boric acid (H3BO3) is * (A) H2BO3- * (B) HBO32- * (C) BO33- * (D) B(OH)4- **Q 47.** The substance that has both sp2 and sp3 hybridisation shown by carbon atom is * (A) Diamond * (C) N2O * (B) Graphite * (D) Graphene **Q 48.** The compound that is not a neutral oxide among the following is * (A) CO * (B) NO * (C) 7 * (D) NO2 **Q 49.** The pH of 10-10 M HCl is * (A)0 * (B) 4 * (C) 7 * (D) 10 **Q 50.** The substance that cannot be prepared from B2H6 is * (A) H3BO3 * (B) BF3 * (C) B2(CH3)6 * (D) Na2B4O10 **Q 51.** The most powerful reducing agent among the following molecules is * (A) H3PO4 * (B) H3PO3 * (C) H3PO2 * (D) H4P2O7 **Q 52.** An enzyme that converts glucose and fructose both into ethanol is * (A) Zymase * (B) Diastase * (C) Maltase * (D) Invertase **Q 53.** The colour of K2Cr2O7 is orange while K2CrO4 is yellow. The option given that holds true is * (A) d-d transition in K2Cr2O7 while charge transfer in K2CrO4 * (B) Charge transfer in K2Cr2O7 while d-d transition in K2CrO4 * (C) d-d transition in both * (D) Charge transfer in both **Q 54.** A solution having pH=3 has been raised to 6. The resulting concentration of H+ is * (A) hundred times more than that of the original solution * (B) hundred times less than that of the original solution * (C) thousand times less than that of the original solution * (D) thousand times more than that of the original solution **Q 55.** The pair that has maximum and minimum Lewis acid character is * (A) BI3, BF3 * (C) BCl3, BF3 * (B) BF3, BI3 * (D) BBr3, BF3 **Q 56.** The total entropy change (ΔS total) for the system and surrounding of a spontaneous process is * (A) ΔS Total = ΔSsys - ΔSsurr> 0 * (B) ΔS Total = ΔSsys + ΔSsurr > 0 * (C) ΔS Total = ΔSsys - ΔSsurr = 0 * (D) ΔS Total = ΔSsys + ΔSsurr = 0 **Q 57.** The chemistry of corrosion is considered as * (A) Oxidation Phenomenon * (C) Electrochemical Phenomenon * (B) Reduction Phenomenon * (D) Optical Phenomenon **Q 58.** Carbon is a unique element because * (A) it forms four bonds, although the ground state configuration would predict the formation of fewer bonds. * (B) it shows catenation property. * (C) it forms covalent bond instead of ionic bond. * (D) it has two stable isotopes, carbon-12 and carbon-13. **Q 59.** If the equilibrium constant for a reaction, 2XY(g) X2(g) + Y2 (g) is 144 The equilibrium constant for the reaction, ½ X2 (g) + ½ Y2 (g) XY(g) is * (A) 144 * (B) 12 * (C) 1/100 * (D) 1/12 **Q 60.** A 0.62g of sample of Na2CO3.H2O is added to 100ml of 0.1NH2SO4, the resulting solution is * (A) Acidic * (B) Neutral * (C) Basic * (D) Amphoteric **Q 61.** CFSE for a high spin complex is zero. Its electronic configuration is * (A) t2g3 e2g * (B) t2g4 e2g * (C) t2g5 e2g * (D) t2g6 e0g **Q 62.** Fe+2 forms a high spin octahedral complex, its magnetic moment is * (A) 5.92 BM * (B) 0 BM * (C) 1.73 BM * (D) 4.01 BM **Q 63.** The most stable complex is * (A) [Co(en)(H2O)4]+2 * (C) [Co(NH3)6]+3 * (B) [Co(en)2(H2O)2]+2 * (D) [Co(en)3]+3 **Q 64.** The outer electronic configuration of the most electronegative element is * (A) ns2 np4 * (B) ns2 np5 * (C) ns2 np6 * (D) ns2 np3 **Q 65.** The two products of ozonolysis are acetone and acetaldehyde. The parent alkene is * (A) propene * (C) 2 methyl But-2-ene * (B) But-2-ene * (D) 2 methyl Propene **Q 66.** Neutral oxides CO, N2O or NO react with * (A) base not with acid * (C) neither acid nor base * (B) acid not with base * (D) both acid and base **Q 67.** The number of enantiomers obtained from mono-chlorination of 2 - methyl butane is * (A) 2 * (B) 3 * (C) 4 * (D) 5 **Q 68.** The cation not considered as Lewis acid but comes under purview of Bronsted acid is * (A) Al+3 * (B) Cu+2 * (C) NH4+ * (D) Ag+ **Q 69.** The relation between Standard Free Energy (ΔG) and Equilibrium Constant (K) of a reaction is * (A) ΔG = -RTlnK * (C) ΔG = -RTlogK * (B) ΔG = -2.303RTInK * (D) Option A & B both **Q 70.** The process that initiates photochemical chlorination of alkane is * (A) Cracking * (B) Homolysis * (C) Pyrolysis * (D) Substitution **Q 71.** For a cell, Zn(s)/Zn2+(0.1M)//Ag+(0.01M)/Ag(s) emf of the cell and standard free energy change (ΔG°) at 25°C (298K) is (E°Ag+/Ag = +0.799V and E°Zn2+/Zn = -0.763V) * (A) E° = 1.4732V, ΔG°= -284.33kJ * (C) E° =1.4732V, ΔG°= -28.433kJ * (B) E°=0.14732V, ΔG°= -284.33k * (D) E° =0.14732V, ΔG°= -284.33k **Q 72.** The reaction that is used to prepare Trans alkenes is * (A) Mannich reaction * (C) Lindlar catalyst * (B) Birch reduction * (D)Sebatier Sendrens reaction **Q 73.** The substance that does not have hydrogen bond is * (A) H3O2 * (C) H2O * (B) H2O2 * (D) H3O+ **Q 74.** The incorrect statement for Chemisorption is * (A) Multilayer adsorption occurs. * (C) Heat of adsorption is relatively high. * (B) Adsorption equilibrium is irreversible. * (D) Appreciable activation energy is involved. **Q 75.** The correct alternative that holds true for the Assertion and Reason below is Assertion: We feel comfortable in hot and humid climate. Reason: Sweat evaporates faster in humid climate. * (A) Both Assertion and Reason are true and Reason is correct explanation of Assertion * (B) Both Assertion and Reason are true and Reason is not the correct explanation of Assertion. * (C) Assertion is true but Reason is false. * (D) Both Assertion and Reason are false **Q 76.** When a solute is dissolved in a solvent volume of solution * (A) remains equal to the volume of solvent. * (C) increases as compared to the solvent. * (B) may vary depending on conditions. * (D) becomes less than that of the solvent. **Q 77.** Natural rubber is a long-chain hydrocarbon polymer consisting of a monomer called * (A) isoprene * (B) styrene * (C) tetrefluoroethylene * (D) epoxide **Q 78.** Which of the following could act as a propellant for rockets? * (A) Liquid hydrogen + liquid nitrogen * (B) Liquid oxygen + liquid argon * (C) Liquid hydrogen + liquid oxygen * (D) Liquid nitrogen + liquid oxygen **Q 79.** Refer to the scheme below to identify the unknown substances. Solid X + Excess of aqueous ammonia – White precipitate Solution X + Excess aqueous KOH + Aluminium foil and warm → Colourless solution + Gas Y The option that holds true for the solid X and gas Y is | Solid X | Gas Y | |---|---| | (A) Sodium hydroxide | Water vapour | | (B) Calcium hydroxide | Water vapour | | (C) Aluminium nitrate | Ammonia | | (D) Zinc nitrate | Ammonia | **Q 80.** In the US a bilateral meeting of America and China held in 2024 led to stop drug trafficking of * (A) Cocaine * (B) Codeine * (C) Morphine * (D) Fentanyl

CONTECH 24 Past Paper PDF

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