Question

a student extracts the colour from some green smarties and uses paper chromatography to separate components colours. she finds blue has a rf=0.38 and yellow rf=0.75 this suggests the blue is more strongly adsorbed onto the stationary phase and is less soluble in the mobile phase. the blue is more strongly adsorbed onto the stationary phase and is less soluble in the mobile phase. the yellow is more strongly adsorbed onto the stationary phase and is more soluble in the mobile phase. the yellow is more strongly adsorbed onto the stationary phase and is less soluble in the mobile phase.

Explanation:

Step1: Recall the formula for \(R_f\) value

\(R_f=\frac{\text{distance moved by solute}}{\text{distance moved by solvent}}\)
A lower \(R_f\) value means the solute is more strongly adsorbed onto the stationary phase (as it doesn't move as far with the mobile phase). A higher \(R_f\) value means the solute is more soluble in the mobile phase (as it moves further with the mobile phase).

Step2: Analyze the \(R_f\) values of blue and yellow

Blue has \(R_f = 0.38\) (lower value) and yellow has \(R_f=0.75\) (higher value).
Since blue has a lower \(R_f\) value, it is more strongly adsorbed onto the stationary phase and less soluble in the mobile phase.

Answer:

the blue is more strongly adsorbed onto the stationary phase and is less soluble in the mobile phase.