The student could use a plastic or polystyrene cup or add a lid to minimize heat loss. This improves the investigation as it helps to maintain the temperature throughout the reaction, allowing for more accurate readings.

Description

The table shows that as the concentration of copper sulfate increases, the increase in temperature also increases, reaching a maximum increase of 35°C at 0.7 moles per dm³. This indicates a correlation between concentration and temperature change.

Explanation

Initially, the temperature change increases with the concentration due to a higher number of reactant molecules, which leads to more effective collisions and higher energy release during the reaction. However, after 0.7 moles per dm³, the temperature increase levels off, suggesting that once the copper sulfate concentration exceeds a certain point, there may be an excess of reactant, causing no further energy increase despite ongoing reactions.