DP Chemistry (last assessment 2024)
Question 18M.2.sl.TZ2.e
| Date | May 2018 | Marks available | [Maximum mark: 2] | Reference code | 18M.2.sl.TZ2.e |
| Level | sl | Paper | 2 | Time zone | TZ2 |
| Command term | Determine | Question number | e | Adapted from | N/A |
e.
[Maximum mark: 2]
18M.2.sl.TZ2.e
A student determined the percentage of the active ingredient magnesium hydroxide, Mg(OH)2, in a 1.24 g antacid tablet.
The antacid tablet was added to 50.00 cm3 of 0.100 mol dm−3 sulfuric acid, which was in excess.
Determine the mass of Mg(OH)2 in the antacid tablet.
[2]
Markscheme
n(Mg(OH)2) «= n(H2SO4) =» = 0.00382/3.82 × 10–3 «mol»
m(Mg(OH)2) «= 0.00382 mol × 58.33 g mol–1» = 0.223 «g»
Award [2] for correct final answer.
[2 marks]
