AP BIOLOGY

Detailed explanation-1: -Using the chromatogram, Rf values can be calculated with the equation distance moved by substance / distance moved by solvent. As seen earlier, the distance moved by substance is the distance from the start line to the centre of the spot.

Detailed explanation-2: -Rf = (distance moved by pigment)/ (distance moved by solvent)

Detailed explanation-3: -Define Retardation Factor It is the ratio of the time that a substance spends in the stationary phase to the time that it spends in the mobile phase. Therefore in Rf= Ds/Df, where RF is the retardation factor, Ds is the migration distance of the substance and Df is the migration distance of the solvent front.

Detailed explanation-4: -The retention factor (Rƒ) may be defined as the ratio of the distance travelled by the solute to the distance travelled by the solvent. It is used in chromatography to quantify the amount of retardation of a sample in a stationary phase relative to a mobile phase.