Question

Relative to the solvent level in the developing chamber, how high should the spots be?

a) Slightly above
b) Below
c) At the same level
d) Variable

Answer 1

In Thin Layer Chromatography (TLC), the spots of the sample should be applied below the solvent level to prevent them from dissolving when the solvent moves up the plate.

Step-by-step explanation:

Relative to the solvent level in the developing chamber for chromatography, the spots should be below the solvent level. If the spots were at the same level or above the solvent, they would dissolve into the solvent when it rises through the stationary phase via capillary action. It's important that the initial spots of the sample are placed just above the base of the chromatography plate and definitely below the solvent level to ensure a successful separation of components.