MCAT Organic Question — Chlorines Molecule

  • Reviewed By: Liz Flagge
  • Consider the following two molecules:

    molecules

    The two molecules above can be described as:

    A) enantiomers.

    B) diastereomers.

    C) tautomers.

    D) conformers.

    Explanation

    The molecule on the left has the chlorines in the cis configuration, while the one on the right has them arranged trans. Cis and trans are a type of diastereomer. Thus (B) is the right answer.

    A: Enantiomers are mirror images of each other. The mirror image of a cis arrangement would still be cis, thus this is incorrect.

    C: Tautomers are a form of constitutional isomer in which the bonding between the atoms is changed. The molecules depicted have the same bonding arrangment, so they are not tautomers. Also, by far the most common tautomer on the MCAT is the ketone / enol tautomer, which this is not.

    D: Conformers can be freely interconverted by rotation around a single bond, with no bond-breaking. Here, there’s no way to convert between cis and trans without breaking bonds.

    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 expert using the form below. No obligation, just expert advice.

    Schedule My Free Consultation

    Leave a Reply

    Your email address will not be published. Required fields are marked *