Question: Acetylene, C, H, is a colorless gas which burns with a brilliant flame. Acetylene torches are used by welders for cutting and soldering metals. Acetylene is produced by the reaction of calcium carbide, CaC2,(s), in water according to the following equation: CaC2,(s) + 2H2O(l) —-> C2H2(g) + Ca(OH)2(aq)

How many moles of CaC2 (s) must react with water to produce 2.25 moles C2H2(g)?
[Explain your answer.]