The rate of alpha halogenation is independent of the concentration (or identity) of the halogen. The rate depends only on the concentration of aldehyde or ketone. What does that tell you? The best conclusion must be that halogen does not participate in the rate determining step of the reaction. What is the rate determining step? The answer is enolization.

Can you think of some 'wrong' answers a test-writer might think up to put with correct ones like these above within an MCAT multiple choice question? Here's one. Maybe they would try to trick you with some half remembered idea from enzyme kinetics, even though there is no enzyme involved, like trying to get you to agree that halogen must be present in greater than saturating concentration. Try not to think like the test-writers too much! It will change your view of human nature.












The WikiPremed MCAT Course is a comprehensive course in the undergraduate level general sciences. Undergraduate level physics, chemistry, organic chemistry and biology are presented by this course as a unified whole within a spiraling curriculum. Please read our policies on Privacy and Shipping & Returns.  Contact Us. MCAT is a registered trademark of the Association of American Medical Colleges, which does not endorse the WikiPremed Course. WikiPremed offers the customers of our publications or our teaching services no guarantees regarding eventual performance on the MCAT.


Creative Commons License
WikiPremed is a trademark of Wisebridge Learning Systems LLC. The work of WikiPremed is published under a Creative Commons Attribution NonCommercial ShareAlike License. There are elements of work here, such as a subset of the images in the archive from WikiPedia, that originated as GNU General Public License works, so take care to follow the unique stipulations of that license in printed reproductions.