DP Chemistry (first assessment 2025)

Test builder »

Question 19N.2.SL.TZ0.b

Select a Test
Date November 2019 Marks available [Maximum mark: 2] Reference code 19N.2.SL.TZ0.b
Level SL Paper 2 Time zone TZ0
Command term Outline, State Question number b Adapted from N/A
b.
[Maximum mark: 2]
19N.2.SL.TZ0.b

Outline two laboratory methods of distinguishing between solutions of citric acid and hydrochloric acid of equal concentration, stating the expected observations.

[2]

Markscheme

Any two of:

«electrical» conductivity AND HCl greater ✔

pH AND citric acid higher ✔

titrate with strong base AND pH at equivalence higher for citric acid ✔

add reactive metal/carbonate/hydrogen carbonate AND stronger effervescence/faster reaction with HCl ✔

titration AND volume of alkali for complete neutralisation greater for citric acid ✔

titrate with strong base AND more than one equivalence point for complete neutralisation of citric acid ✔

titrate with strong base AND buffer zone with citric acid ✔

 

NOTE: Accept “add universal indicator AND HCl more red/pink” for M2.

Accept any acid reaction AND HCl greater rise in temperature.

Accept specific examples throughout.

Do not accept “smell” or “taste”.

Syllabus sections