Blueprint MCAT Formerly Next Step
Return to Blog Homepage

MCAT Organic Chemistry Question — Alcohol Reactions

  • by Kerry Goldstein
  • Mar 20, 2015
  • MCAT Blog, MCAT Organic, MCAT Question of the Day

Considering all “-R” groups to be alkyl groups, which alcohol is most reactive in an SN1 reaction with HCl?

a) primary alcohol

b) secondary alcohol

c) tertiary alcohol

d) number of substituent groups does not affect alcohol reactivity

 

 

Explanation

Only tertiary alcohols form a carbocation stable enough for an SN1 mechanism. Primary and secondary alcohols react too slowly by SN1 mechanisms to for significant amounts of product in comparison with tertiary alcohols.

a) primary alcohol, incorrect, Primary alcohols do not form stable carbocations necessary for the SN1 mechanism with HCl.

b) secondary alcohol, incorrect, Same reason as choice a).

c) tertiary alcohol, correct.

d) number of substituent groups does not affect alcohol reactivity, incorrect, Substituent groups strongly affect alcohol reactivity, and primary and secondary alcohols do not react significantly with HCl by an SN1 mechanism.

 

Want more MCAT practice?

We’ve got options for every schedule and learning style!

From the best online MCAT course created by top instructors with 524+ MCAT scores to the most representative full-length practice exams and private tutoring, we can custom tailor your MCAT prep to your goals!

Not sure which option is right for you? Schedule a free MCAT consultation with an MCAT Advisor using the form below. No obligation, just expert advice.

Schedule My Free Consultation

Submit a Comment