Question

How many grams of NH3 form when 27.5L of H2 (measured at STP)react with N2 to form NH3 according to:
N2(g) + 3H2 (g) = 2NH3 (g)

Answer 1

Here is an example of a stoichiometry problem. Just follow the steps. To convert L H2 to moles, remember that 1 mole of a gas occupies 22.4 L at STP.
http://www.jiskha.com/science/chemistry/stoichiometry.html

Post your work if you get stuck.