Solution: The following table lists some enthalpy of formation values for selected substances.Substance                ΔH° f (kJ/mol)NaOH(aq)                  -469.1MgCl2(s)                    -641.8NaCl(aq)                    -407.3Mg(OH)2(s)               -924.5H2O(l)                       -285.8Determine the enthalpy for this reaction:MgCl2(s) + 2NaOH(aq) → Mg(OH)2(s) + 2NaCl(aq)Express your answer in kilojoules per mole to four significant figures.

Problem

The following table lists some enthalpy of formation values for selected substances.

Substance                ΔH° f (kJ/mol)

NaOH(aq)                  -469.1

MgCl2(s)                    -641.8

NaCl(aq)                    -407.3

Mg(OH)2(s)               -924.5

H2O(l)                       -285.8

Determine the enthalpy for this reaction:

MgCl2(s) + 2NaOH(aq) → Mg(OH)2(s) + 2NaCl(aq)

Express your answer in kilojoules per mole to four significant figures.