Determine the grams of ammonia produced when 1.15 g of hydrogen H_2 is reacted with 3.75 g of nitrogen N_2 to produce ammonia (NH_3) according to the following chemical equation: 3H_2 + N_2 → 2NH_3

Question

Determine the grams of ammonia produced when 1.15 g of hydrogen H is reacted with 3.75 g of nitrogen N to produce ammonia (NH) according to the following chemical equation:

3H + N → 2NH

Answer 1

3H₂ + N₂ → 2NH₃

Since this equation is in units of "moles", we need to convert 1.15 g of H₂ and 3.75 g of N₂ into moles to use it.

The molar mass of H₂ is: (1.008)2 = 2.016 g/mol

The molar mass of N₂ is: (14.007)2 = 28.014 g/mol

So for H₂: (1.15 g)/(2.016 g/mol) = 0.57044 moles

For N₂: (3.75 g)/(28.014 g/mol) = 0.13386 moles

The chemical reaction equation requires 3 moles of H₂ for every 1 mole of N₂ so I can see that I have extra H₂. Since I have 0.13386 moles of N₂, I only need 3(0.13386) = 0.40158 moles of H₂ and I have excess of that. So N₂ is my limiting reactant, meaning we use that to calculate the product.

The chemical reaction equation says that for every 1 mole of N₂, there are 2 moles of NH₃ produced so since there are 0.13386 moles of N₂, then (0.13386)2 = 0.26772 moles of NH₃ are produced.

The molar mass of NH₃ is: (14.007)1 + (1.008)3 = 17.031 g/mole

(17.031 g/mol)(0.26772 moles) = 4.56 g NH₃