Measuring enthalpy changes of reactions
2 marks · HardIn a calorimetry experiment, a student measures a temperature decrease during the reaction.
Explain what this temperature change tells you about the type of reaction and the direction of energy transfer.
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.
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Also accept: The reaction is endothermic; energy is taken in from the surroundings; It is an endothermic reaction because heat energy is absorbed from the surroundings
Common mistakes: Stating exothermic instead of endothermic; Not mentioning direction of energy transfer
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Marking points
B1 · 1 mark · States the reaction is endothermic or heat is absorbed
B2 · 1 mark · Mentions energy transfer is from surroundings to reaction/chemicals
Worked solution
A decrease in temperature means the reaction is endothermic—energy has been absorbed from the surroundings into the chemicals.