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## AP®︎/College Chemistry

### Unit 3: Lesson 9

Separation of solutions and mixtures chromatography

# Separation of solutions and mixtures chromatography

AP.Chem: SPQ‑3 (EU), SPQ‑3.C (LO), SPQ‑3.C.1 (EK)

## Problem

A chemist is separating a mixture of two substances, X and Y, using column chromatography. The chemist loads the mixture onto a column filled with silica gel (a polar material) and then flows a nonpolar solvent through the column. Partway through running the column (at t, equals, t, ’), the chemist observes the separation of X and Y shown below.
Which substance, X or Y, has the stronger attraction for the stationary phase, and why?