Measuring enthalpy changes of reactions
3 marks · EasyA student wants to measure the enthalpy change for the reaction: Describe three steps the student should take to ensure the experiment is as accurate as possible.
Name one way to reduce heat loss during the experiment.
State one way to improve the accuracy of temperature measurement.
Give one way to ensure that the reaction mixture is uniform during the experiment.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
Show answer
(a) Use a lid or insulation (e.g., polystyrene cup)
(b) Use a thermometer with finer scale (0.1 °C) or repeat and average readings
(c) Stir the mixture
Show mark scheme and worked solution
Marking points
B1 (a) · 1 mark · Names one method to reduce heat loss (e.g., use a lid, insulation, polystyrene cup).
B1 (b) · 1 mark · States a method to get more accurate temperature measurements (e.g., digital thermometer, 0.1 °C thermometer, averaging readings).
B1 (c) · 1 mark · States 'stirring the mixture' (or equivalent) for uniformity.
Worked solution
a) Use a lid or polystyrene cup to reduce heat loss.
b) Use a thermometer that measures to 0.1 °C or repeat and average temperature readings.
c) Stir the mixture to ensure uniform temperature throughout.