DP Chemistry (last assessment 2024)
Question 18M.2.sl.TZ2.1c
| Date | May 2018 | Marks available | [Maximum mark: 1] | Reference code | 18M.2.sl.TZ2.1c |
| Level | sl | Paper | 2 | Time zone | TZ2 |
| Command term | Calculate | Question number | c | Adapted from | N/A |
c.
[Maximum mark: 1]
18M.2.sl.TZ2.1c
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.
(c)
The excess sulfuric acid required 20.80 cm3 of 0.1133 mol dm−3 NaOH for neutralization.
Calculate the amount of excess acid present.
[1]
Markscheme
«n(H2SO4) = × n(NaOH) = (0.02080 dm3 × 0.1133 mol dm–3)»
0.001178/1.178 × 10–3 «mol»
[1 mark]
