Answer to Question #164082 in General Chemistry for Ron

Question

1. Which element will have 5 electrons in its Lewis dot symbol?

a. Argon

b. Boron

c. Carbon

d. Phosphorus

e. Sulfur

2. Which of the following elements can only form one bond in a Lewis structure?

a. O

b. C

c. N

d. Al

e. H

3. Write the correct Lewis dot structure for O2. Which statement correctly describes the structure of 

the whole molecule?

a. There is a double bond and four lone pairs.

b. There is a double bond and six lone pairs.

c. There is a single bond and four lone pairs.

d. There is a single bond and six lone pairs.

e. There is a single bond, a double bond, and six lone pairs.

4. The electron pair in a C - F bond could be considered…

a. Closer to C because Carbon has a larger radius and thus exerts greater control over the 

shared electron pair

b. Closer to F because Fluorine has a higher electronegativity than Carbon

c. Closer to C because Carbon has a lower electronegativity than Fluorine

d. An inadequate model since the bond is ionic

e. Centrally located directly between the C and F

5. Considering the position of the elements in the periodic table and their relative electronegativities 

and bond polarities, which bond is longest?

a. carbon - Oxygen triple bond

b. carbon - Oxygen single bond

c. carbon - Carbon single bond

d. carbon - Carbon double bond

e. carbon - Nitrogen triple bond

6. Which bond is the strongest?

a. carbon - Nitrogen triple bond

b. carbon - Nitrogen double bond

c. carbon - Hydrogen bond

d. carbon - Carbon triple bond

e. carbon - Carbon single bond

7. Predict qualitatively the relative bond lengths of the four single bonds given below and arrange 

them from shortest to longest:

C-N N-O N-Si O-O

a. O-O < N-SI < C-N < N-O

b. O-O < N-O < C-N < N-Si

c. O-O < C-N < N-O < N-Si

d. N-O < O-O < C-N < N-Si

e. N-Si < C-N < N-O < O-O

8. Which of the following represents a non-polar covalent bond?

a. H-O

b. C-N

c. C-C

d. Li-F

e. S-O

9. Based on electronegativities, which of the following would you expect to be most ionic?

a. N2

b. CaF2

c. CO2

d. CH4

e. CF4

10. Which element is the least electronegative?

a. Calcium

b. Cesium

c. Iron

d. Barium

e. Potassium

11. Which of the following statements about resonance is true?

I. Resonance hybrids occur because a compound changes back and forth between two or 

more resonance structures.

II. Resonance structures differ in the arrangement of electrons but not in the arrangement of 

atoms.

III. Resonance hybrids contain delocalized electrons.

IV. Resonance structures for a given compound always contribute equally to the resonance 

hybrid.

V. Resonance structures occur when there are two or more valid Lewis structures for a given 

compound.

VI. Resonance hybrids are a composite of resonance structures.

a. I, II, V, VI

b. I, II, V, VI

c. II, III, IV, VI

d. II, III, V, VI

e. II, IV, V, VI

12. How many resonance forms will nitrate ion (NO3-) have?

a. -1

b. 0

c. 1

d. 2

e. 3

13. A list of non-metals is given below. Which elements cannot exceed the octet rule? 

B Si N P O S F Cl

a. Si, P, S, Cl

b. B, N, O, F

c. O, S, F, Cl

d. B, Si, N, P

e. All eight elements can exceed the octet rule.

14.Write the singly bonded Lewis dot structure for BF3. Which of the following statements best 

describes this structure?

a. It obeys the octet rule on all atoms.

b. It has less than an octet on at least one atom.

c. It has a lone pair of electrons on the boron atom.

d. It has less than an octet of electrons on all atoms.

e. It exceeds the octet rule.

15. Using the VSEPR theory, give the electron pair orientation and predict the geometry of the 

following:

a. CH3I

b. SiH4

c. NF3

d. SCN– (C is the middle atom)

e. H2S

16. Give the bond angles for the molecules given in #15.

17. The molecule, acetone, has the following Lewis structure.

a. What is the geometry of the first carbon?

b. What are the bond angles around the first carbon?

c. What is the geometry of the middle carbon?

d. What are the bond angles around the middle carbon?

Answer 1

1. b

2. e

3. a

4. b

5. c

6. e

7. b

8. e

9. b

10. b

11. c

12. e

13. d

14. b

15. a- tetrahedral

b- tetrahedral( trigonal planar)

c- tetrahedral

d- tetrahedral( linear)

e- tetrahedral

16. a- $120°$

b- $109.5°$

c- $102.5°$

d- $180°$

e- $109.5°$

17. No structure provided for the question.