In the reaction N2+3H2-2NH3, if 20.0g of hydrogen react How many Liters of nitrogen are needed

Question

Please show work this question has been stumping me for a couple hours.

Answer 1

A couple of hours? Really?

20.0 g H2 x 1 mole/2g = 10.0 moles

Moles of N2 needed = 10.0 mol H2 x 1 mol N2/3 mol H2 = 3.33 moles N2 

The volume of N2 occupied by 3.33 moles will depend on the temp and pressure. The problem is incomplete as it does not specify these parameters. Assuming STP, then 3.33 moles x 22.4 L/mole  = 74.7 liters