Consider the reaction below. 2h2o 2h2 + o2 how many moles of hydrogen are produced when 6.28 mol of oxygen form?
a. 3.14 mol
b. 6.28 mol
c. 12.6 mol
d. 25.2 mol

1) Write the balanced equation

2 H2O > 2 H2 + O2

2) State the molar ratios:

2 mol H2O : 2 mol H2 : 1 mol O2.

3) Write the proportion with the theoretical ratios and the actual data:

[2 mol H2 / 1 mol O2 ] = x mol H2 /  6.28 mol O2]

You can realize that this tells that the number of moles of H2 produced is the double of the number of moles of O2 produced.

4) Solve for x

x = 6.28 mol O2 *  2 mol H2 / 1 mol O2 = 12.56 mol O2.

option C. 12.6 mol