A student investigated the temperature change during the neutralization reaction of dilute hydrochloric acid (HCl\text{HCl}HCl) and sodium hydroxide (NaOH\text{NaOH}NaOH) solution in a glass beaker.
The student added portions of 4 cm34\text{ cm}^34 cm3 of dilute hydrochloric acid to 20 cm320\text{ cm}^320 cm3 of sodium hydroxide solution and recorded the temperature after each addition. The results are shown in the table below:
| Volume of dilute HCl\text{HCl}HCl added (cm3\text{cm}^3cm3) | Temperature (∘C^\circ\text{C}∘C) |
|---|---|
| 4 | 19.8 |
| 8 | 20.7 |
| 12 | 21.6 |
| 16 | 22.5 |
| 20 | 23.4 |
| 24 | 24.3 |
The recorded temperatures follow a linear relationship.
Name a container the student could use instead of a glass beaker to minimize heat loss to the surroundings and improve the accuracy of the results.
The starting temperature of the sodium hydroxide solution corresponds to the yyy-intercept of the line of best fit (where the volume of acid added is 0 cm30\text{ cm}^30 cm3). Determine this starting temperature in ∘C^\circ\text{C}∘C.
13 exam-style questions on AQA GCSE Chemistry 5.1 Exothermic and endothermic reactions, covering 5.1.1 Energy transfer during exothermic and endothermic reactions, 5.1.2 Reaction profiles, and 5.1.3 The energy change of reactions (HT only). Each one has a worked solution and a mark scheme showing where the marks go.