2. Calculate the enthalpy change to be expected for the reaction NaCl(s) --> NaCl(aq).

Use Hess's law, an enthalpy change that was measured in this experiment, and the

data from the following table:

Reaction DH (kJ/mol)

1/2 H2(g) + 1/2 Cl2(g) --> HCl(g) –92.3

Na(s) + 1/2 O2(g) + 1/2 H2(g) --> NaOH(s) –426.8

Na(s) + 1/2 Cl2(g) --> NaCl(s) –411.1

H2(g) + 1/2 O2(g) --> H2O(l) –285.8

HCl(g) --> HCl(aq) –75.2

NaOH(s) --> NaOH(aq) –41.8