| Date | May 2014 | Marks available | 1 | Reference code | 14M.1.SL.TZ2.12 |
| Level | Standard level | Paper | Paper 1 | Time zone | Time zone 2 |
| Command term | Question number | 12 | Adapted from | N/A |
Question
An ideal gas is contained in a thermally insulated cylinder by a freely moving piston.
The gas is compressed by the piston and as a result the temperature of the gas increases. What is the explanation for the temperature rise?
A. The rate of collision between the molecules increases.
B. Energy is transferred to the molecules by the moving piston.
C. The molecules of the gas are pushed closer together.
D. The rate of collision between the molecules and the walls of the cylinder increases.
Markscheme
B
Examiners report
The weaker candidates were opting for D. But D does not answer the question which asks for an explanation for the temperature rise.
