Question

How many moles of C2H2 are needed to react completely with 84 mol O2

Answer 1

Balanced chemical equation:

2 C2H2 + 5 O2 = 4 CO2 + 2 H2O

2 moles C2H2 ---------------- 5 moles O2
moles C2H2 ------------------ 84 moles O2

moles C2H2 = 84 * 2 / 5

molesC2H2 = 168 / 5 => 33.6 moles of C2H2