If 6.20 mol of calcium carbide (CaC2) reacts with an excess of water, how many moles of acetylene (C2H2), a gas used in welding, will be produced?

Question

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

Answer 1

Use the coefficients in the balanced equation to convert anything to anything.
6.20 mol CaC2 x (1 mol C2H2/1 mol CaC2) = 6.20 x 1/1. = 6.20 mols C2H2.