Question

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)

Answer 1

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