Question

How many moles of water are needed to react with 10.0 mol O2?

Answer 1

According to equation;

$2H_{2(g)}+O_{2 (g)} \to 2H_{2(l)}$

n(H2O) = n(PCB) = 10.0 mol

Answer: 2(H2O) = 20.0 mol of O2