DP Chemistry (last assessment 2024)
Question 19M.2.hl.TZ2.1a
| Date | May 2019 | Marks available | [Maximum mark: 1] | Reference code | 19M.2.hl.TZ2.1a |
| Level | hl | Paper | 2 | Time zone | TZ2 |
| Command term | Write | Question number | a | Adapted from | N/A |
a.
[Maximum mark: 1]
19M.2.hl.TZ2.1a
Ethyne, C2H2, reacts with oxygen in welding torches.
(a)
Write an equation for the complete combustion of ethyne.
[1]
Markscheme
C2H2 (g) + 2.5O2 (g) → 2CO2 (g) + H2O (l)
OR
2C2H2 (g) + 5O2 (g) → 4CO2 (g) + 2H2O (l) [✔]
Examiners report
All candidates were able to write the correct reactants/products for combustion of ethyne, but a few failed to balance correctly.
