How do you set up this equation

I'm so upset at myself for forgetting all this chem stuff.

Given the equation: 3H2(g) + N2(g) --> 2NH3(g) ... calculate the following:

a) the mass of NH3 formed when 1.34mol of N2 reacts w/ excess of H2
b) the mass of N2 required to form 1.00kg of NH3
c) the volume of H2(g) required to react completely with 23.5g of N2 at STP

3H2(g) + N2(g) --> 2NH3(g)
1.34moles N2 x (2NH3 / 1N2) x 17g/mole = 45.56g NH3

1000g NH3 / 17g/mole = 58.82moles NH3

58.82moles NH3 x (1N2/2NH3) x 28g/mole = 823.53g N2 required

23.5g N2 / 28g/mole = 0.839moles N2

0.839moles N2 (3H2 / 1N2) = 2.52moles H2 required
2.52moles x 22.4L/mole = 56.4L H2 required