Answer:
2.138 I think
Explanation:
N2 + 3H2 -> 2NH3
This means that 3 moles of H2 gives 2 moles of NH3
Lets convert 12.12 g of NH3 into moles.
The molecular weight of NH3 is 17 g/mol
So 12.12 g is 0.713 moles
If 2 NH3 comes from 3 moles of H2
1 mole comes from 1.5 moles of H2
So 0.713 moles of NH3 comes from 1.5 x 0.713 moles of H2 =1.069 moles of H2
1 mole of H2 weights 2g
So 1.069 moles of H2 weighs 2.138 g