9.02.7 Past Paper Q & A
3
a. Black food colouring is a mixture/ is not pure
. It contains three colours
b. Distance to ink C = 0.8 & Distance to solvent front = 2.8
- Rf = 0.8/2.8 = 2.85
- 4.89 (2 sf)
(*distance values depend on size of picture, Rf value does not)
