Calculate Δrh for the following reaction: MgO(s) + CO₂(g) → MgCO₃(s). Use the following reactions and given Δrh's:
Mg(s) + CO₂(g) → MgCO₃(s) Δrh = -702.5 kJ/mol
2Mg(s) + O₂(g) → 2MgO(s) Δrh = -1203.2 kJ/mol
a) -500.7 kJ/mol
b) -900.7 kJ/mol
c) -1505.7 kJ/mol
d) -1905.7 kJ/mol