DP Chemistry (first assessment 2025)
Question 19N.1A.SL.TZ0.13
Date | November 2019 | Marks available | [Maximum mark: 1] | Reference code | 19N.1A.SL.TZ0.13 |
Level | SL | Paper | 1A | Time zone | TZ0 |
Command term | Derive | Question number | 13 | Adapted from | N/A |
13.
[Maximum mark: 1]
19N.1A.SL.TZ0.13
Questions 13 and 14 are about an experiment to measure the enthalpy of combustion, ΔHc, of ethanol, using the apparatus and setup shown.
What is the enthalpy of combustion, ΔHc, of ethanol in kJ mol−1?
Maximum temperature of water: 30.0°C
Initial temperature of water: 20.0°C
Mass of water in beaker: 100.0 g
Loss in mass of ethanol: 0.230 g
Mr (ethanol): 46.08
Specific heat capacity of water: 4.18 J g−1 K−1
q = mcΔT
A.
B.
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D.
[1]
Markscheme
C
Syllabus sections
Reactivity 1. What drives chemical reactions? » Reactivity 1.1—Measuring enthalpy changes » Reactivity 1.1.4—The standard enthalpy change for a chemical reaction, ΔH⦵, refers to the heat transferred at constant pressure under standard conditions and states. It can be determined from the change in temperature of a pure substance. Apply the equations Q = mcΔT and ΔH = − Qn in the calculation of the enthalpy change of a reaction.