MCAT Organic Chemistry Review

Analyzing Organic Reactions

Practice Questions

1.    Which of the following are Lewis bases?

1.    Ag+

2.    H2O

3.    NH3

1.    I only

2.    I and II only

3.    II and III only

4.    I, II, and III

2.    Rank the following in order of decreasing nucleophilicity in an aprotic solvent: RO, RCOOH, ROH, HO

1.    RCOOH > ROH > RO > HO

2.    HO > ROH > RO > RCOOH

3.    RO > HO > ROH > RCOOH

4.    RCOOH > RO > HO > ROH

3.    Rank the following in order of decreasing electrophilicity: CR3+, CH3OH, CH3OCH3, CH3Cl

1.    CH3OCH3 > CR3+ > CH3OH > CH3Cl

2.    CR3+ > CH3OH > CH3OCH3 > CH3Cl

3.    CH3OCH3 > CH3Cl > CR3+ > CH3OH

4.    CR3+ > CH3Cl > CH3OH >CH3OCH3

4.    Rank the following in order of decreasing leaving group ability: H2O, HO, Br, H

1.    H2O > Br > HO > H

2.    H2O > HO > Br > H

3.    HO > Br > H2O > H

4.    HO > H > H2O > Br

5.    Rank the following in order of decreasing oxidation state: amine, carboxylic acid, aldehyde, alkane

1.    Aldehyde, amine, alkane, carboxylic acid

2.    Carboxylic acid, aldehyde, amine, alkane

3.    Carboxylic acid, amine, aldehyde, alkane

4.    Alkane, amine, aldehyde, carboxylic acid

6.    If cinnamaldehyde was treated with LiAlH4, what reaction would occur?

1.    Reduction, resulting in a primary alcohol

2.    Oxidation, resulting in a carboxylic acid

3.    An acid–base reaction, resulting in a diol

4.    No reaction would occur

7.    If 2-butanol was treated with dichromate, what reaction would occur?

1.    Reduction, resulting in the formation of butene

2.    Oxidation, resulting in the formation of butanoic acid

3.    Oxidation, resulting in the formation of butanone

4.    No reaction would occur

8.    If 1-hexanol was treated with pyridinium chlorochromate, what would the end product be?

1.    2-hexanol

2.    2-hexanone

3.    Hexanal

4.    Hexanoic acid

9.    SN1 reactions show first-order kinetics because:

1.    the rate-limiting step is the first step to occur in the reaction.

2.    the rate-limiting step involves only one molecule.

3.    there is only one rate-limiting step.

4.    the reaction involves only one molecule.

10.In a protic solvent, which of the following halogens would be the best nucleophile?

1.    Br

2.    Cl

3.    F

4.    I

11.Which of the compounds below can undergo oxidation?

1.   

2.   

3.   

4.   

12.Treatment of (S)-2-bromobutane with sodium hydroxide results in the production of a compound with an (R) configuration. This reaction has most likely taken place through:

1.    an SN1 mechanism.

2.    an SN2 mechanism.

3.    an SN1 and SN2 mechanism in sequence.

4.    an SN1 and SN2 mechanism simultaneously.

13.Which of the following solvents would be LEAST useful for a nucleophile–electrophile reaction?

1.    H2O

2.    CH3CH2OH

3.    CH3SOCH3

4.    CH3CH2CH2CH2CH2CH3

14.Aldehydes are generally more reactive than equivalent ketones to nucleophiles. This is likely due to differences in:

1.    steric hindrance.

2.    leaving-group ability.

3.    resonance stabilization.

4.    electron-withdrawing character.

15.Which conversion between carboxylic acid derivatives is NOT possible by nucleophilic reaction?

1.    Carboxylic acid to ester

2.    Ester to carboxylic acid

3.    Anhydride to amide

4.    Ester to anhydride

PRACTICE QUESTIONS