Question

An appropriate solvent for a TLC analysis gives Rf values of ____ - _____ with ideal values in the range of _____ - _____.

A) 0.1-0.5, 0.2-0.8
B) 0.5-1.0, 0.8-1.2
C) 0.2-0.8, 0.1-0.5
D) 1.0-1.5, 1.2-1.7

Answer 1

The correct Rf value ranges for an appropriate solvent in TLC analysis are 0.1-0.5, ideally, and 0.2-0.8 overall, therefore the answer is A) 0.1-0.5, 0.2-0.8.

Step-by-step explanation:

An appropriate solvent for a TLC analysis gives Rf values typically between 0.2-0.8, with ideal values generally within the range of 0.2-0.5. The Rf value, or retention factor, represents the relative travel distance of the compound being analyzed about the solvent front on a TLC plate.

An Rf value that is too high or too low may indicate an inappropriate solvent system for the separation desired, as compounds may travel too close to the solvent front or not far enough from the baseline, respectively. The selection of an optimal solvent system is crucial for achieving good separation and accurate results in thin-layer chromatography. Therefore, the correct answer to the student's question would be A) 0.1-0.5, 0.2-0.8.