The thermochemical equation below shows the decomposition of the mineral magnesite:
MgCO3(s) => MgO(s) + CO2(g) ΔHrxn = 117.3 kJ
What is ΔH when 5.35 mol of CO2 reacts with excess MgO?
A. 314 kJ B. -628 kJ C. 628 kJ D. -314 kJ E. none of these is within 5% of the correct value