---
title: "A student sets up a paper chromatography experiment to separate pigments extracted from spinach leaves. Polar filter paper is used as the stationary phase, and a nonpolar organic solvent mixture is used as the mobile phase. As shown in the diagram, the student adds solvent to the beaker such that the liquid level is above the baseline where the spinach extract was spotted. Which of the following best predicts and explains the effect of this procedural error on the experiment?"
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url: "https://nerd-notes.com/ubq/119163/"
date_modified: "2026-08-19T12:32:33+00:00"
---

# A student sets up a paper chromatography experiment to separate pigments extracted from spinach leaves. Polar filter paper is used as the stationary phase, and a nonpolar organic solvent mixture is used as the mobile phase. As shown in the diagram, the student adds solvent to the beaker such that the liquid level is above the baseline where the spinach extract was spotted. Which of the following best predicts and explains the effect of this procedural error on the experiment?

A student sets up a paper chromatography experiment to separate pigments extracted from spinach leaves. Polar filter paper is used as the stationary phase, and a nonpolar organic solvent mixture is used as the mobile phase. As shown in the diagram, the student adds solvent to the beaker such that the liquid level is above the baseline where the spinach extract was spotted. Which of the following best predicts and explains the effect of this procedural error on the experiment?

![A schematic line drawing shows a glass beaker covered with a watch glass. Suspended vertically inside the beaker is a strip of filter paper. Near the bottom of the paper strip is a horizontal dashed line labeled 'Baseline spot' containing a dark solid circle representing the plant extract. The liquid layer at the bottom of the beaker is indicated by a solid line labeled 'Solvent level', which is positioned above the dashed line labeled 'Baseline spot'. No other particles, labels, text, or annotations appear.](https://nerd-notes.com/wp-content/uploads/ubq-frq-generated/stem-fig-1-1787142753-xlWuF9.jpg)

- **A.** The pigments will dissolve directly into the bulk solvent at the bottom of the beaker rather than traveling up the paper by capillary action, preventing separation.
- **B.** The calculated \(R_f\) values for all pigments will increase because the higher initial solvent level accelerates capillary action along the paper strip.
- **C.** The calculated \(R_f\) values for all pigments will decrease because the excess solvent dilutes the mobile phase and lowers its affinity for the pigments.
- **D.** Nonpolar pigments will successfully travel up the paper while polar pigments remain at the baseline, resulting in incomplete separation.

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/119163/*