0654.C12.3.02 — Interpret simple chromatograms to identify: 3 State and use the equation for Rf: (a) . unknown substances by comparison with distance travel: past paper questions
Real questions on 0654.c12.3.02 — interpret simple chromatograms to identify: 3 state and use the equation for rf: (a) . unknown substances by comparison with distance travel
The newest 5 of 5 written questions. Open one to see it on the real paper.
- 0654/43 · May/June 2025 · Q5b[1]
and (b) State which two measurements on Fig. 5.1 are needed to calculate the R f value of spot X.
See it on the paper → - 0654/43 · May/June 2025 · Q5c[2]
The student calculates the R f value of spot Y to be 0.80. The distance travelled by spot Y is 2.8 cm. Calculate the distance travelled by the solvent. distance travelled by solvent = cm
See it on the paper → - 0654/43 · May/June 2025 · Q5d[2]
Paper chromatography has a stationary phase and a mobile phase. The stationary phase is a solid. The mobile phase is a liquid. Describe what happens to the separation and motion of the particles when a solid changes to a liquid. separation motion
See it on the paper → - 0654/12 · May/June 2023 · Q14[1]
Which apparatus is used to separate a mixture of these two liquids?
See it on the paper → - 0654/11 · October/November 2019 · Q22[1]
Which diagram shows the correct way to set up the apparatus?
See it on the paper →
What examiners said
Stronger candidates chose the correct distances. B and C, A and D and A and C were all popular.
— Examiner report, May/June 2025, 0654/43 Q5(b) (Cambridge)
Stronger candidates calculated the value correctly although many inverted the division or multiplied the distances.
— Examiner report, May/June 2025, 0654/43 Q5(c) (Cambridge)
Few candidates appreciated that the particles only move slightly further apart. Incorrect responses included spreading out, moving apart from each other and separating. Many gave the separation in the liquid rather than the change from a solid to a liquid. More knew that the motion increased from vibrating to moving over each other. Again, many described the motion of the liquid but not the change...
— Examiner report, May/June 2025, 0654/43 Q5(d) (Cambridge)
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