Organic Chemistry MCAT Practice Exam

Disable ads (and more) with a membership for a one time $2.99 payment

Master Organic Chemistry for the MCAT. Use flashcards and multiple choice questions to understand concepts, with each question offering hints and detailed explanations. Prepare effectively for your exam!

Each practice test/flash card set has 50 randomly selected questions from a bank of over 500. You'll get a new set of questions each time!

Practice this question and more.

In ion exchange chromatography, what type of ion does cation exchange retain?

Negative ions
Neutral ions
Positive ions
Large ions

The correct answer is: Positive ions

In ion exchange chromatography, specifically cation exchange, the process is designed to retain cations, which are positively charged ions. In this type of chromatography, stationary phases are typically composed of negatively charged functional groups that will attract and bind to the positively charged ions in the sample mixture. Cations are held onto the stationary phase through electrostatic interactions, allowing negatively charged species (anions) and neutral molecules to pass through the column without significant interaction. As a result, cation exchange chromatography effectively separates and retains positively charged ions while allowing other types of ions and uncharged species to elute. This selectivity is essential for the purification and separation processes in various applications, such as water treatment, protein purification, and analytical chemistry, where specific ions need to be isolated or analyzed.