Chemistry MDCAT Unit-6: Chemical Bonding

Study Notes

The exact value of the angle in BF3 is 120°.
Molecules with non-planar geometry include CH4, NH4+, MnO4-, and NF3.
Sigma bonds are formed when two partially filled atomic orbitals overlap in such a way that the probability of finding the electron is maximum around the line joining the two nuclei.
The angle between un-hybridized p-orbital and three sp2 hybrid orbitals of each carbon atom is 120°.
Fe will form the most ionic bond with F-.
AB4 type molecules with no lone pairs enable the formation of a regular tetrahedral shape.
The compound with the greatest difference of electronegativity is HF.
The bond formed by overlapping of sp2 and p orbitals is found in BF3.
During the formation of a chemical bond, energy decreases.
Hydrogen bonds are not primary bonds.
Non-planar molecules include SO2, C2H4, and BF3.
Ionic bonds have the least electronegativity difference between bonding atoms.
The element with the lowest first ionization energy is N.
The percentage of ionic and covalent character in HF is 43% and 57%, respectively.

The compromised distance between two hydrogen atoms in a hydrogen molecule is 74 pm.
The radius of an atom cannot be measured precisely because the atom has no sharp boundary, and the size of the atom changes from one compound to another.
Covalent radius is half of the bond distance between two similar atoms covalently bonded in a molecule.
The energy gap between 2nd ionization energy and 3rd ionization energy is very large for elements with Z values belonging to I-A, II-A, III-A, and IV-A.
The central atom of AB4 molecules carries bond pair-bond pair repulsions only.
The percentage of s-character in hybrid orbitals indicating the longest bond length is 25%.
The hybridization of carbon number 1 in 1-Propene is sp2.
The molecular geometry of a species with 3 bond pairs and 1 lone pair is trigonal pyramidal.
The shape of the carbonate ion is trigonal planar.

The element with the highest electronegativity is F.
The high value of the first ionization energy of nitrogen compared to oxygen is due to its half-filled p-subshell.
Electronegativity of elements increases from left to right along a period.
Ionic character in a compound can be calculated by (ionic μ / observed μ) × 100.
The bond energy depends on electronegativity difference, bond length, and atomic radius.

The bond between carbon and oxygen in CO2 is a covalent bond.
The strength of a bond between two atoms depends on electronegativity difference, bond length, and atomic radius.
The shortening of bonds is due to the predominant participation of s-orbital in hybridization.
The carbon-carbon sigma bond in ethyne molecule is formed by overlapping between sp-orbitals of carbon atoms.
The bond in fluorine molecule is formed by the overlapping of p-orbitals on each atom of fluorine.

Ammonia (NH3) can form a bond with boron trifluoride (BF3) by supplying electrons.
The bond between carbon and oxygen in CO2 is a covalent bond.
The specie with the highest ionic character is CsF.