Question

How many moles of O2 are produced in the decomposition of 24 g of water in the

following reaction?
2H20 - 2H2 + O2

Answer 1

M of water = 2(1) + 16 = 18 g/mol
n of water = 24g/(18g/mol) = 4/3 mol
n of H2O : n of O2 = 2 : 1
2:1 = 4/3 : x
x = (4/3)/2 = 2/3 mol of O2