Given reaction:
MgCl2(s) + 2NaOH(aq) → Mg(OH)2(s) + 2NaCl(aq)
Formula:
ΔH°rxn = ∑nΔH°f(products) - ∑nΔH°f(reactants)
= [ΔH°f(Mg(OH)2) + 2ΔH°f(NaCl)] -[ΔH°f(Mg(Cl)2 + 2ΔH°f(NaOH)]
= [-924.7+2(-407.2)] - [-641.6+2(-470.1)] = -157.3 kJ/mol
Ans: Enthalpy for the reaction is -157.3 kJ/mol
