Chromatography may be used to separate and identify the dyes in a mixture. Which statement is correct?
- AA dye with an $R_f$ value of 1.2 can be present in a mixture.
- BA dye could have a different $R_f$ value if a different solvent was used.
- CAll blue dyes have the same $R_f$ value.
- DChromatography can only be used for coloured substances such as dyes.