Question

Explain how the heat measured in Example 5.5 differs from the enthalpy change for the exothermic reaction described by the following equation: HCl(aq)+NaOH(aq)→NaCl(aq)+H₂O(l).

a) The heat measured is the same as enthalpy change.
b) The heat measured includes the calorimeter's heat capacity.
c) The heat measured accounts for the specific heat of the solution.
d) The heat measured is the negative of enthalpy change.

Answer 1

The heat measured in Example 5.5 differs from the enthalpy change for the exothermic reaction. The heat measured includes the calorimeter's heat capacity, while the enthalpy change only represents the heat released by the reaction. Option b

Step-by-step explanation:

The heat measured in Example 5.5 differs from the enthalpy change for the exothermic reaction described by the equation HCl(aq)+NaOH(aq)→NaCl(aq)+H₂O(l). The correct answer is b) The heat measured includes the calorimeter's heat capacity.

In Example 5.5, the heat measured includes not only the heat released by the reaction, but also the heat absorbed by the calorimeter itself. The calorimeter's heat capacity, which is the ability of the calorimeter to absorb heat, needs to be accounted for when determining the heat measured.

The enthalpy change for the reaction, on the other hand, represents the heat released by the reaction alone and does not take into account the heat absorbed by the calorimeter.

Therefore, the correct answer is b) The heat measured includes the calorimeter's heat capacity.