Question

1. based on the $r_f$ values of samples a and b, which sample is more attracted to the mobile phase?

both sample a and sample b are equally attracted to the mobile phase.
sample a has a lower retention factor than sample b so it is more attracted to the mobile phase.
sample a has a higher retention factor than sample b, so it is more attracted to the mobile phase.
sample b has a higher retention factor so it is more attracted to the mobile phase.

Explanation:

The retention factor \(R_f\) is calculated as \(R_f=\frac{\text{distance traveled by sample}}{\text{distance traveled by solvent front}}\). A higher \(R_f\) value means the sample travels a greater distance, indicating stronger attraction to the mobile phase (as it moves more with the mobile - phase).

Answer:

Sample A has a higher retention factor than Sample B, so it is more attracted to the mobile phase.