The following balanced equation shows the formation of water.
2h2 + o2 → 2h2o
how many moles of oxygen (o2) are required to react completely with 1.67 mol h2?
a) 0.835 mol o2

b) 1.67 mol o2

c) 3.34 mol o2

A) 0.835 mol of

Explanation: According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.

As can be seen from the given balanced equation:

2 moles of hydrogen are required to react completely with 1 mole of oxygen.

Thus 1.67 moles of hydrogen will react with= moles of oxygen.