A quantity of 1.6 g sample of is decomposed in a bomb calorimeter. The temperature of the calorimete — Thermodynamics and Thermochemistry Chemistry Question

💡 Solution & Explanation

Molar mass of $\text{NH}_4\text{NO}_3$ = $80\text{ g/mol}$. Moles decomposed = $1.6 / 80 = 0.02\text{ mol}$. Heat absorbed by the reaction from the calorimeter $q = C\Delta T = 1.25 \times 6.0 = 7.5\text{ kJ}$. Molar heat = $7.5 / 0.02 = 375\text{ kJ/mol}$. (Since temperature decreases, the reaction is endothermic and thus positive).