Use the data in the appendix and the following thermochemical equation to determine the enthalpy of formation of MgCO₃(s). (The H_f of MgCl₂(s) = -641.60 kJ/mol.)

MgCO₃(s) + 2 HCl(g) MgCl₂(s) + CO₂(g) + H₂O(l) H = -24 kJ

HCl = -92.30 kJ/mol

CO2= -393.51 kJ/mol

H2O= -285.83 kJ/mol