Question SPM.2.HL.TZ0.8
| Date | May Specimen-2023 | Marks available | [Maximum mark: 6] | Reference code | SPM.2.HL.TZ0.8 |
| Level | HL | Paper | 2 | Time zone | TZ0 |
| Command term | Calculate, Explain, Suggest | Question number | 8 | Adapted from | N/A |
Small pieces of solid paraffin with a total mass of 30 g at a temperature of 42 °C are mixed with 150 g of liquid paraffin at a temperature of 240 °C. The mixture is stirred until an equilibrium temperature is reached.
The following data for paraffin are available:
Specific heat capacity of solid paraffin = 0.7 kJ kg−1 K−1
Specific heat capacity of liquid paraffin = 2.13 kJ kg−1 K−1
Specific latent heat of fusion of paraffin = 220 kJ kg−1
Melting point of paraffin = 47 °C
Calculate the theoretical equilibrium temperature of the mixture.
[3]
One heat capacity term correctly substituted ✓
latent heat correctly substituted ✓
«°C» ✓
When the experiment was carried out, the equilibrium temperature of the mixture was found to be different from the theoretical value.
Suggest the reason for this difference.
[2]
Experimental temperature will be lower ✓
Heat loss to the environment ✓
The mixture was held in a large metal container during the mixing.
Explain one change to the procedure that will reduce the difference in (b)(i).
[1]
Insulate the container
OR
Carry out experiment quicker
OR
Use larger volumes of substances ✓