The table below records the temperature changes and calculated enthalpy changes, ΔH\Delta HΔH, for two aqueous processes, Reaction P and Reaction Q.
| Temperature at the start of the reaction (∘C^\circ\text{C}∘C) | Temperature at the end of the reaction (∘C^\circ\text{C}∘C) | Enthalpy change ΔH\Delta HΔH (kJ/mol\text{kJ/mol}kJ/mol) | |
|---|---|---|---|
| Reaction P | 19.419.419.4 | 27.127.127.1 | −57.3-57.3−57.3 |
| Reaction Q | 20.220.220.2 | 13.513.513.5 | +26.4+26.4+26.4 |
Classify each of the two reactions, Reaction P and Reaction Q, as either exothermic or endothermic. You must justify your classifications by referencing both the temperature changes and the signs of the enthalpy changes.
The student carried out these experiments in an open glass beaker. The measured temperature change is smaller in magnitude than theoretical predictions due to significant heat exchange with the surrounding environment.
Suggest two distinct ways in which the student could modify the experimental setup to minimize this heat transfer.