DP Chemistry (last assessment 2024)
Question 18M.2.sl.TZ2.b.ii
| Date | May 2018 | Marks available | [Maximum mark: 2] | Reference code | 18M.2.sl.TZ2.b.ii |
| Level | sl | Paper | 2 | Time zone | TZ2 |
| Command term | State and explain | Question number | b.ii | Adapted from | N/A |
b.ii.
[Maximum mark: 2]
18M.2.sl.TZ2.b.ii
Graphing is an important tool in the study of rates of chemical reactions.
Excess hydrochloric acid is added to lumps of calcium carbonate. The graph shows the volume of carbon dioxide gas produced over time.
State and explain the effect on the rate of reaction if ethanoic acid of the same concentration is used in place of hydrochloric acid.
[2]
Markscheme
rate decreases
OR
slower reaction
«ethanoic acid» partially dissociated/ionized «in solution/water»
OR
lower [H+]
Accept “weak acid” or “higher pH”.
[2 marks]