The combustion of $\pu{2.350 mmol}$ of $\ce{X}$ caused the temperature of a bomb calorimter to rise from $23.700 °C$ to $26.300 °C$. Assume $T = 25.000 °C$, $H_\text{comb} = -3310 \frac{kJ}{mol}$, and $ng = -3 \frac{\text{mol gas}}{\text{mol X}}$ for the combustion and determine the heat capacity of the calorimeter.

I am having some difficulty determining if the process I did is correct for this problem. So I used the equation $∆H=c∆T + ∆ngRT$. I first determined $∆H$ to be $\pu{-7.7785 kJ}$ by multiplying $\pu{0.00235 mol}$ to $\pu{-3310kJ/mol}$. The rest I just plugged into the equation and got $c$ to be $2855.75$. I am not sure if that's the correct answer but I don't feel very confident with my process. I would appreciate any help and feedback.

  • $\begingroup$ Are you sure of your data ? Your change of temperature is extremely low. It means that the heat capacity of the calorimeter is high. 99% of the heat is used for heating the calorimeter. It seems odd, or even dubious. The heat capacity I get is 2966 J/K. It is enormous ! $\endgroup$ – Maurice Feb 11 at 21:46

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.