Question

CaO(s) + 3C(s) > CaC2(s) + CO(g)

deltaHrxn = +464.8 kJ/mol-rxn

Is the reaction endothermic or exothermic? What is the enthalpy change if 10.0 g of CaO is allowed to react with an excess of carbon?

Answer 1

If delta Hrxn is +, the reaction is endothermic. Look at the problem. 464.8 kJ of heat is needed to react with (how much) CaO. That is 56 g. So the heat needed to convert 10.0 g must be
464.8 kJ x 10.0/56 = ??

Answer 2

exothermic and 82.9kj