Question

Nitrogen and hydrogen react to produce ammonia according to the following equation.

N₂ + 3H₂ → 2NH₃

The molar mass of nitrogen (N) is 14 g/mol. The molar mass of hydrogen (H) is 1 g/mol. When the reaction starts with 42 grams of nitrogen (N₂), how many moles of ammonia are produced?

a) 3
b) 51
c) 17
d) 2

Answer 1

To solve the problem:

1. Calculate the number of moles of nitrogen present:
Number of moles = Mass / Molar mass
Number of moles of N₂ = 42 g / 28 g/mol = 1.5 mol

2. Use the balanced chemical equation to calculate the moles of ammonia produced:
From the equation, we can see that 1 mole of N₂ reacts with 2 moles of NH₃
Therefore, 1.5 mol of N₂ will react with (2/1) x 1.5 mol of NH₃ = 3 mol of NH₃

So the answer is (a) 3.