Question 1

Which of the following best describes the concept of electronegativity?

Accepted Answer

The ability of an atom to attract electrons to itself in a chemical bond.

Question 2

Which of the following compounds is expected to have the highest lattice energy?

Accepted Answer

$$\mathrm{MgO}$$

Question 3

Place the following bonds in order of increasing ionic character: $$\mathrm{Si-F}$$, $$\mathrm{Si-Cl}$$, $$\mathrm{Si-Br}.$$

Accepted Answer

$$\mathrm{Si-Br} \u003c \mathrm{Si-Cl} \u003c \mathrm{Si-F}$$

Question 4

Which of the following statements about metallic bonding is FALSE?

Accepted Answer

Metals are brittle due to directional bonding.

Question 5

Which of the following molecules has the largest dipole moment in the gas phase?

Accepted Answer

$$\mathrm{CH_3Cl}$$

Question 6

How many bonding pairs and lone pairs of electrons are in $$\mathrm{H_2O}$$?

Accepted Answer

2 bonding pairs and 2 lone pairs

Question 7

Which of the following bonds is the strongest according to bond energies?

Accepted Answer

$$\mathrm{N \equiv N}$$

Question 8

Which of the following reactions is associated with the lattice energy of $$\mathrm{$$CaCl_2$$}$$?

Accepted Answer

$$\mathrm{Ca$$^{2+}$$(g) + 2Cl^-(g) \rightarrow $$CaCl_2$$(s)}$$

Question 9

Which of the following molecules contains a polar covalent bond?

Accepted Answer

$$\mathrm{HCl}$$

Question 10

Which of the following best explains why the lattice energy of $$\mathrm{MgO} is $$much larger than that of $$\mathrm{NaCl}$$?

Accepted Answer

The charges on $$\mathrm{Mg$$^{2+}$$}$$ and $$\mathrm{O$$^{2-}$$}$$ are greater than those on $$\mathrm{Na^+}$$ and $$\mathrm{Cl^-}.$$

Question 11

Which of the following bonds is the weakest?

Accepted Answer

$$\mathrm{I_2$}$$

Question 12

Which of the following molecules has the greatest number of resonance structures?

Accepted Answer

$$\mathrm{NO_3$^-}$$

Question 13

Which of the following is the best Lewis structure for $$\mathrm{CO_3$^{2-}}$$?

Accepted Answer

A structure with one C=O double bond and two C-O single bonds, with all O atoms having a formal charge of -1/3.

Question 14

Which of the following compounds would be expected to have the lowest melting point?

Accepted Answer

$$\mathrm{I_2$}$$

Question 15

Which of the following elements is the most electronegative?

Accepted Answer

$$\mathrm{F}$$

Question 16

Which of the following best describes a single covalent bond?

Accepted Answer

A bond formed by sharing one pair of electrons between two atoms.

Question 17

Which of the following molecules has the highest bond order?

Accepted Answer

$$\mathrm{N_2$}$$

Question 18

Which of the following best explains why $$\mathrm{H_2O} is a $$polar molecule?

Accepted Answer

The molecule has a bent shape and the O-H bonds are polar.

Question 19

Which of the following best describes the formal charge on the central atom in $$\mathrm{NO_3$^-}$$?

Accepted Answer

The formal charge on N is 0.

Question 20

Which of the following molecules has the greatest number of lone pairs on the central atom?

Accepted Answer

$$\mathrm{$$XeF_4$$}$$

Chemical Bonding I: The Lewis Model – Study Notes and Practice Guide

Study Guide - Practice Questions