DP Chemistry (last assessment 2024)
Question 19M.1.hl.TZ2.19
| Date | May 2019 | Marks available | [Maximum mark: 1] | Reference code | 19M.1.hl.TZ2.19 |
| Level | hl | Paper | 1 | Time zone | TZ2 |
| Command term | Question number | 19 | Adapted from | N/A |
19.
[Maximum mark: 1]
19M.1.hl.TZ2.19
Several reactions of calcium carbonate with dilute hydrochloric acid are carried out at the same temperature.
CaCO3 (s) + 2HCl (aq) → CaCl2 (aq) + H2O (l) + CO2 (g)
Which reaction has the greatest rate?
[1]
Markscheme
A
Examiners report
74 % of the candidates chose the correct combination to give the greatest rate of reaction. The most commonly chosen distractor was D where “smaller surface area of same mass of CaCO3(s)” was chosen. It seems these candidates confused “surface area” with “particle size”.