The balanced chemical equation for the synthesis reaction of ammonia is
Now, in order to determine the number of liters of ammonia that can be produced, you need the masses of the reactants. The only way to solve for liters produced is to use the number of moles of ammonia produced.
To get the number of moles of ammonia produced, you need the number of moles of nitrogen and the number of moles of hydrogen that react.
If you're able to calculate the number of moles of ammonia produced, you can use the ideal gas law equation to solve for volume
Here's a sample calculation. Assuming 1 mole of nitrogen and 3 moles of hydrogen react
SIDE NOTE Do not forget to convert the temperature from degrees Celsius to Kelvin and the pressure, which I assume is in mmHg or torr, to atm.