Retrieval Practice 2

Question 1

Which of the following bonds has the smallest dipole moment?

A) C–H

B) C–N

C) O–H

D) C–C

Answer 1

D) C–C

Question 2

Complete the formula for the following neutral compound: CH_?Cl₂

? =

Answer 2

2

Question 3

Which of the following molecules has a net, non-zero formal charge?

A) NH₂OH

B) NH₄

C) CH₃Br

D) H₂O

Answer 3

B) NH4

Question 4

Which of the following statements is NOT true regarding the carbonate dianion (CO₃^2-)?

A) All of the oxygen atoms bear the same amount of charge.

B) It is a base.

C) All of the carbon-oxygen bonds are the same length.

D) The carbon atom bears the negative charge.

Answer 4

D) The carbon atom bears the negative charge.

Question 5

Which of the following bonds has the largest dipole moment?

A) C-O

B) Li-O

C) C-H

D) C-C

Answer 5

B) Li-O

Question 6

Which of the following atoms has the lowest electronegativity?

A) Hydrogen

B) Carbon

C) Boron

D) Sodium

Answer 6

D) Sodium

Question 7

Considering resonance, what is the charge on each oxygen atom in the nitrate ion, -NO3?

A) -1/2

B) -1

C) -2/3

D) +1

Answer 7

C) -2/3

Question 8

The value of the equilibrium constant, Keq for the following equilibrium is…

HCl + H2O ⇌ H3O+ + Cl—

HCl pKa —7; H3O+ pKa —2

*“Large” = absolute value greater than 1; “Small” = absolute value less than 1

A) It cannot be determined based on the information given

B) Large* and negative

C) Small* and positive

D) Large* and positive

E) Small* and negative

Answer 8

D) Large* and positive

Question 9

Which of the following molecules has trigonal planar geometry?

A) CH₄

B) CH₃^-

C) NH₄⁺

D) BF₃

Answer 9

D) BF₃

Question 10

What is the value of the equilibrium constant, Keq, for the following reaction?

C₂H₂ + H₂N^- ⟶ HC₂^- + NH₃

pKa C₂H₂ = 25

pKa NH₃ = 38

A) 10^-13

B) 10¹³

C) –13

D) 25/38

E) 38/25

F) 13

Answer 10

B) 10¹³

Question 11

Each of the following molecules has a net molecular dipole moment, except?

A) CH₂F₂

B) CH₃CH2Br

D) C₂H₄

E) CH₃Cl

Answer 11

D) C₂H₄

Question 12

Which atomic orbitals on Carbon overlap to form the π-bonding molecular orbital of ethene, H2C=CH2?

A) C 2sp² + C 2sp²

B) C 2sp³ + C 2sp3

C) C 2p + C 2p

D) C 2sp² + C 2p

Answer 12

C) C 2p + C 2p

Question 13

Which of the following molecules has a net molecular dipole moment?

A) ethene, H₂C=CH₂

B) 1,2-dibromoethane, BrCH₂CH₂Br

C) methyl fluoride, CH3F

D) ethane, CH₃CH₃

Answer 13

C) methyl fluoride, CH3F

Question 14

Which sets of curved arrows accounts for the reaction of propene with HI?

Answer 14

A

Question 15

Which of the following forms the strongest conjugate base?

A) CH₃OH, pKa 16

B) NH₃⁺, pKa 10

C) CH≡CH, pKa 25

D) CH₃CH₃, pKa 50+

Answer 15

D) CH₃CH₃, pKa 50+

Question 16

How many ketones have the molecular formula C₅H₁₀O?

A) 5

B) 4

C) more than 5

D) 3

Answer 16

D) 3

Question 17

Which of the following concepts can be used to rationalize the observation that acetic acid is a stronger acid than methanol?

A) atom size

B) valence shell electron pair repulsion theory

C) electronegativity

D) resonance

Answer 17

D) resonance

Question 18

Each of the following molecules has a net molecular dipole moment, except?

Answer 18

D

Question 19

Which of the following molecules is NOT linear?

A) ethyne, C₂H₂

B) ammonia, NH₃

C) iodine, I2

D) nitrogen, N₂

Answer 19

B) ammonia, NH₃

Question 20

Which of the following terms describes the reactivity of trimethylamine, (CH3)3N?

A) Lewis acid but not a Brønsted-Lowry acid

B) Lewis base but not a Brønsted-Lowry base

C) Brønsted-Lowry base and Lewis base

D) Brønsted-Lowry acid and Lewis acid

Answer 20

C) Brønsted-Lowry base and Lewis base