| Date | May 2016 | Marks available | 2 | Reference code | 16M.2.SL.TZ0.3 |
| Level | Standard level | Paper | Paper 2 | Time zone | Time zone 0 |
| Command term | Suggest | Question number | 3 | Adapted from | N/A |
Question
In an experiment to determine the specific latent heat of fusion of ice, an ice cube is dropped into water that is contained in a well-insulated calorimeter of negligible specific heat capacity. The following data are available.
Mass of ice cube = 25g
Mass of water = 350g
Initial temperature of ice cube = 0˚C
Initial temperature of water = 18˚C
Final temperature of water = 12˚C
Specific heat capacity of water = 4200Jkg−1K−1
Using the data, estimate the specific latent heat of fusion of ice.
The experiment is repeated using the same mass of crushed ice.
Suggest the effect, if any, of crushing the ice on
(i) the final temperature of the water.
(ii) the time it takes the water to reach its final temperature.
Markscheme
use of m×c×θ with correct substitution for either original water or water from melted ice
energy available to melt ice = «8820 – 1260 =» 7560 J
equates 7560 to mL
3.02×105Jkg–1
FOR EXAMPLE
0.35 × 4200 × (18 – 12) OR 0.025 × 4200 × 12
7560 J
L=\(\frac{7560}{0.025}\)
3.02×105Jkg–1
Award [3 max] if energy to warm melted ice as water is ignored (350kJkg–1).
Allow ECF in MP3.
(i)
no change in temperature/no effect, the energies exchanged are the same
(ii)
the time will be less/ice melts faster, because surface area is greater or crushed ice has more contact with water
