Bonding and Representing Molecules – Practice Questions

Which of the following pairs of atoms are likely to form an ionic bond?

I. potassium and oxygen II. carbon and sulfur III. iron and fluorine

I and III

Which one of the following bonds would be expected to be the most polar?

a. B – I b. C – Br c. P – S d. O – S

d. O – S

Which one of the following bonds would be expected to be the least polar?

a. S – Se b. S – Cl c. N – O d. C – F

a. S – Se

In which of the following bond representations is/are the bond dipole(s) accurately represented?

II and III

Which one of the following correctly represents the bond dipole between carbon and oxygen?

B

Shown below are representations of three different substances, where dark grey represents carbon, light grey/white

represents hydrogen, and red represents oxygen. The images depict the molecular formulas, which shows the actual number

of atoms in the molecule. For which of these substances is/are the empirical formula(s) the same as the molecular formula(s)?

I and III

In which one of the following substances is the central atom an exception to the octet rule?

a. SiCl4 b. BH3 c. CO2 d. NO2

+

BH3

In which one of the following substances must the central atom expand its valence shell beyond 8 electrons?

a. PCl3 b. ICl3 c. NH3 d. (CO3 )^2-

ICl3

How many total valence electrons must be represented in the Lewis structure for (SO4)^2- ?

32

Shown to the right is an incorrect Lewis structure for SO2. Identify the mistake with the structure.

a. Not enough valence e-

s

b. Incomplete octet on sulfur

c. Wrong central atom

d. Formal charge not minimized

d

Shown to the right is an incorrect Lewis structure for OF2. Identify the mistake with the structure.

a. Not enough valence e-s

b. Incomplete octet on oxygen

c. Wrong central atom

d. Incomplete octet on fluorine

a

Which one of the following is the best Lewis structure for the ClO2

- ion, including minimized formal charges?

(ignore the possible existence of resonance structures)

d

13. Which one of the following is the best Lewis structure for N2O, including minimized formal charges?

b

Which one of the following is the best Lewis structure for CSF2, including minimized formal charges?

a

Molecules of which of the following substances is/are likely to exist as a resonance hybrid?

I. NO3

- II. O3 III. SBr2

a. I only b. II and III c. I and II d. I, II and III

c

. How many lone e- pairs must be added to the skeletal structure shown to the right complete the Lewis structure?

a. 0 b. 2 c. 4 d. 6

2

17. Draw Lewis structures for the following compounds, minimizing formal charge. Include resonance structures if applicable.

PF5 BrF2

- NH4

+

KrOCl4 NO2

- SCN-

SF4 H2O NO2

Which of the following skeletal structures has a molecular formula of C4H10?

I. II. III.

a. I only b. II only c. I and III d. I, II and III

c

What is the name of the compound shown to the right?

a. butanoic acid b. propanoic acid c. butanal d. butanol

a

What is the name of the compound shown to the right?

a. ethanoic acid b. methanal c. ethanol d. methylamine

c

What is the name of the compound shown to the right?

a. hexanoic acid b. hexanal c. pentanoic acid d. hexylamine

b

Which of the following formula/name combination for alkanes is/are correct?

I. C3H8 / propane II. C6H12 / hexane III. CH4 / ethane IV. C4H10 / butane

a. I and III b. II and III c. I and IV d. I, II, and IV

C

Identify all functional groups present in the molecule.

• alcohol

• aldehyde

• amine

• carboxylic acid

Identify all functional groups present in the molecule.

• alcohol

• aldehyde

• amine

• carboxylic acid