Chapter 5, Problem 5.38QE

If nitric acid were sufficiently heated, it can be decomposed into dinitrogen pentoxide and water vapor:

$\begin{array}{l}{\text{2HNO}}_{\text{3}}\left(\mathcal{l}\right)\to {\text{N}}_{\text{2}}{\text{O}}_{\text{5}}\left(\text{g}\right)+{\text{H}}_{\text{2}}\text{O}\left(\text{g}\right)\\ \Delta H_{\text{rxn}}=+176\text{kJ}\end{array}$

1. (a) Calculate the enthalpy change that accompanies the reaction of 1.00 kg HNO₃ (ℓ).
2. (b) Is heat absorbed or released during the course of the reaction?