If the acetylene were burned to form water and carbon dioxide, how many kilojoules of energy would be produced from the complete reaction of 20 of calcium carbide?

Question

CaC2(s)+2H2O(l) --> C2H2(g)+Ca(OH)2(s)

Answer 1

20 what? grams?
dHrxn = (n*dHf products) - (n*dHf reactants)
q for 20g = dHrxn x (20/molar mass CaC2)