CIE iGCSE Co-Ordinated Science C12.3 Chromatography Exam Style Questions Paper 1
▶️ Answer/Explanation
A mixture is judged to contain dye X if it produces spots on the chromatogram that match the position (and hence the \(R_f\) value) of every spot seen for X.
Comparing the spot patterns, only mixture P shows spots in exactly the same positions as dye X.
So dye X is present only in mixture P.
✅ Answer: (C)
Comparing the spot patterns, only mixture P shows spots in exactly the same positions as dye X.
So dye X is present only in mixture P.
✅ Answer: (C)
▶️ Answer/Explanation
The spot of ink must be drawn above the level of the solvent so that it is not washed straight off the paper.
The solvent must be in contact with the paper below the spot so that it rises up by capillary action.
Only diagram C shows the spot correctly positioned above the solvent level with the paper standing in the solvent.
✅ Answer: (C)
The solvent must be in contact with the paper below the spot so that it rises up by capillary action.
Only diagram C shows the spot correctly positioned above the solvent level with the paper standing in the solvent.
✅ Answer: (C)
Question
Which process is used to separate a mixture of coloured compounds?
A. chromatography
B. distillation
C. evaporation
D. filtration
▶️Answer/Explanation
Answer: A. chromatography
Explanation: Chromatography is a technique used to separate mixtures of coloured compounds based on their different solubilities in a solvent. The compounds move at different rates, allowing them to be separated.
Question
The colours in an ink can be separated by chromatography. Which diagram shows the correct way to set up the apparatus?
▶️Answer/Explanation
Answer: C
Explanation: In chromatography, the solvent should move up the paper, carrying the ink components with it, and the spot of ink should be placed above the solvent level.