Consider the balanced chemical equation. N2 (g) + 3H2 (g) → 2NH3 (g) How many grams of ammonia, NH3, can be produced from 125 grams of N2 (assume H2 is in excess.)?

Question

Consider the balanced chemical equation.

N₂ (g) + 3H₂ (g) → 2NH₃ (g)

How many grams of ammonia, NH₃, can be produced from 125 grams of N₂ (assume H₂  is in excess.)?

Answer 1

You first need to solve for the moles of N2. This is done by dividing the mass given by the molar mass of N2. The molar mass is calculated by adding the molar mass of all the atoms together.

14.01g/mol N * 2 = 28.02g/mol N2

Using 28.02 as the molar mass of N2 perform the following calculation.

125g / 28.02g/mol = 4.46mol N2

Because the equation in balanced we already know that there are two moles of ammonia produced for every one mole of N2. This means we just need to multiply the number of moles of N2 by 2 in order to get the number of moles of ammonia produced.

4.46mol N2 * (2mol NH3/1mol N2) = 8.92mol NH3

After solving for the moles of ammonia, we need to convert the moles to grams. This is done using the molar mass of ammonia which is solved as follows.

14.01g/mol N2 + 3(1.0079g/mol H) = 17.0337g/mol NH3

The moles of ammonia we found earlier is then multiplied by the molar mass of ammonia to convert it to grams.

8.92mol NH3 * 17.0337g/mol NH3 = 151.94g NH3

Therefore, your answer should be 151.94g of ammonia are produced.