Question 1

Which of the following statements best describes the geometry and hybridization of the central carbon atom in formaldehyde ($$\ce{CH2O}$$)?

Accepted Answer

Trigonal planar geometry; $$sp^2$$ hybridization

Question 2

Given the following acid-base reaction, which side is favored at equilibrium?

$$\ce{CH3COOH + NH3  CH3COO^- + NH4^+}$$

Given $$pK_a$$ values: $$pK_a ($$acetic acid) = 4.8, $$pK_a ($$ammonium ion) = 9.2.

Accepted Answer

The reactants ($$\ce{CH3COOH + NH3}) $$are favored

Question 3

Which of the following molecules is a secondary alcohol?

Accepted Answer

$$\ce{(CH3)2CHOH} ($$isopropanol)

Question 4

Which of the following pairs are enantiomers?

Accepted Answer

Two molecules that are non-superimposable mirror images

Question 5

Which of the following best explains why $$\ce{(R)-2-butanol} is $$optically active?

Accepted Answer

It contains a chiral center and is not superimposable on its mirror image

Question 6

Which of the following is the most stable conformation of butane ($$\ce{C4H10}) $$when viewed down the C2–C3 bond in a Newman projection?

Accepted Answer

Anti conformation (methyl groups $$180^{\circ}$$ apart)

Question 7

Which of the following statements about Markovnikov’s rule is correct?

Accepted Answer

In the addition of $$\ce{HBr} to $$propene, the bromine atom attaches to the more substituted carbon

Question 8

Which of the following is the best resonance structure for the acetate ion ($$\ce{CH3COO^-}$$)?

Accepted Answer

Both oxygen atoms share the negative charge equally, with one double bond and one single bond to carbon

Question 9

Which of the following factors most increases the rate of an $$\ce{SN2}$$ reaction?

Accepted Answer

Using a primary alkyl halide and a strong nucleophile

Question 10

Which of the following is the correct IUPAC name for the molecule shown below?

$$\ce{CH3CH2CH=CH2}$$

Accepted Answer

1-butene

Question 11

Which of the following statements about the E2 elimination mechanism is correct?

Accepted Answer

It requires a strong base and a good leaving group, and the hydrogen and leaving group must be anti-coplanar

Question 12

Which of the following is the best nucleophile in a polar aprotic solvent?

Accepted Answer

$$\ce{F^-}$$

Question 13

Which of the following statements about resonance is correct?

Accepted Answer

Resonance delocalizes electrons, increasing the stability of a molecule

Question 14

Which of the following is the strongest acid?

Accepted Answer

$$\ce{CH3COOH} ($$acetic acid), $$pK_a \approx 4.8$$

Question 15

Which of the following best describes a meso compound?

Accepted Answer

A compound with chiral centers but is achiral due to an internal plane of symmetry

Question 16

Which of the following statements about Zaitsev’s rule is correct?

Accepted Answer

The most substituted alkene is the major product in an elimination reaction

Question 17

Which of the following best explains why tertiary carbocations are more stable than secondary or primary carbocations?

Accepted Answer

They are stabilized by hyperconjugation and inductive effects from three alkyl groups

Question 18

Which of the following is the correct relationship between the two molecules below?

Molecule A: $$\ce{CH3CH2CH2OH}$$

Molecule B: $$\ce{CH3CH(OH)CH3}$$

Accepted Answer

Constitutional isomers

Question 19

Which of the following best describes the effect of increasing the size of the leaving group in an $$\ce{SN1}$$ reaction?

Accepted Answer

It increases the reaction rate because larger leaving groups are better able to stabilize the negative charge

Question 20

Which of the following best explains why $$\ce{NaOH} is a $$stronger base than $$\ce{NH3}$$?

Accepted Answer

$$\ce{OH^-} is $$less stabilized by resonance and has a higher electron density than $$\ce{NH3}$$

Organic Chemistry Key Skills: Structured Study Guide (Chem 8A)

Study Guide - Practice Questions