Question

The flame in a torch used to cut metal is produced by burning acetylene(C2H2) in pure oxygen. Assuming the combustion of 1 mole of acetylene releases 1251kj of heat, what mass of acetylene is needed to cut through a piece of steel if the process requires 36.658 x 10^4 kj of heat?

Answer 1

(1251 kJ/mol C2H2) x ? mol C2H2 = 36.658E4 kJ.
Solve for ? mols C2H2 and convert to g by g = mols x molar mass.