Chemistry 5070 · O Level · Exothermic and endothermic reactions
Exothermic and endothermic reactions — practice question
The student pours $25\text{ cm}^3$ of $1.0\text{ mol dm}^{-3}$ hydrochloric acid into a glass beaker, takes the temperature, then adds $30\text{ cm}^3$ of aqueous potassium hydroxide in excess and notes the highest temperature reached.
(a)[2]
From the diagram, fill in the table for initial temperature, final temperature and temperature change.
(b)[1]
Use the information in the table in (a) to suggest the type of reaction occurring.
(c)[2]
Predict the temperature change if $2.0\text{ mol dm}^{-3}$ hydrochloric acid is used instead of $1.0\text{ mol dm}^{-3}$. Explain your answer.
(d(i))[1]
Suggest why the temperature change was smaller than expected.
(d(ii))[1]
Suggest one improvement to the experiment that would bring the measured temperature nearer to the expected value.
Worked solution & mark scheme
This 7-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Initial reading = 19.0 and final reading = 28.0” …