Water can be formed in the following reaction:

2H2+O2--->2H2O,

If you have 8 moles of Hydrogen gas (H2), how many moles of Oxygen gas (O2) will you need to make as much water as possible?

(Enter just the number; not the number and units)

The moles of oxygen gas (O2) that is needed is 4 moles

Explanation

2H2 + O2 → 2H2O

The moles of O2 is determined using the mole ratio of H2:O2

that is from equation above H2:O2 is 2:1

If the moles of H2 is 8 moles therefore the moles of O2

= 8 moles x 1/2 = 4 moles