Question 22M.2.SL.TZ2.2a
| Date | May 2022 | Marks available | [Maximum mark: 2] | Reference code | 22M.2.SL.TZ2.2a |
| Level | SL | Paper | 2 | Time zone | TZ2 |
| Command term | Calculate | Question number | a | Adapted from | N/A |
Calculate the number of gas particles in the cylinder.
[2]
Correct conversion of T «T = 310 K» seen ✓
« use of = to get » 2.3 × 1023 ✓
Allow ECF from MP1 i.e., T in Celsius (Result is 2.7 x 1024)
Allow use of n, R and NA
a) This was well answered with the majority converting to K. Quite a few found the number of moles but did not then convert to molecules.
bi) Well answered. It was pleasing to see how many recognised the need to state that the mass/number of molecules stayed the same as well as stating that the volume increased. At SL this recognition was less common so only 1 mark was often awarded.
bii) This was less successfully answered. A surprising number of candidates said that the internal energy of an ideal gas increases during an isothermal expansion. Many recognised that constant temp meant constant KE but then went on to state that the PE must increase and so the internal energy would increase.
