DP Chemistry (last assessment 2024)
Question 19M.3.sl.TZ1.2b(iii)
| Date | May 2019 | Marks available | [Maximum mark: 2] | Reference code | 19M.3.sl.TZ1.2b(iii) |
| Level | sl | Paper | 3 | Time zone | TZ1 |
| Command term | State | Question number | b(iii) | Adapted from | N/A |
b(iii).
[Maximum mark: 2]
19M.3.sl.TZ1.2b(iii)
Powdered zinc was reacted with 25.00 cm3 of 1.000 mol dm−3 copper(II) sulfate solution in an insulated beaker. Temperature was plotted against time.
(b(iii))
The formula q = mcΔT was used to calculate the energy released. The values used in the calculation were m = 25.00 g, c = 4.18 J g−1 K−1.
State an assumption made when using these values for m and c.
[2]
Markscheme
Note: Accept “copper(II) sulfate/zinc sulfate” for “solution”.
Examiners report
Again relatively few gained these marks for stating that it was assumed the density and specific heat of the solution were the same as water.
