For the haber process, n2 + 3h2 → 2nh3, what volume of nitrogen is consumed at stp if you collect 44.8 l of ammonia in excess hydrogen (n = 14 amu, h = 1 amu) ?

Answer is: 22,4 l of nitrogen.

Chemical reaction: 3H₂ + N₂ ⇄ 2NH₃.

V (NH₃) = 44,8 l = 44,8 dm³.

V (N₂) = ?

n (NH₃) = V (NH₃) : Vm

n (NH₃) = 44,8 dm³ : 22,4 dm³/mol

n (NH₃) = 2 mol.

from reaction: n (N₂) : n (NH₃) = 1 : 2

n (N₂) : 2 mol = 1 : 2

n (N₂) = 1 mol.

V (N₂) = n (N₂) · Vm

V (N₂) = 1 mol · 22,4 dm³/mol = 22,4 dm³.

Vm - molar volume