How would you determine the number of moles of #N_2# that are required to produce 12 mol of #NH_3# using the equation: #N_2+ 3H_2 -> 2NH_3#?

2 Answers
Mar 15, 2017

Use the mole ratio of #(NH3)/ N_2#the ratio is 2:1 or 1:2 so it will take 6 moles of #N_2 # to make 12 moles of #NH_3#

Explanation:

There is no coefficient in front of the #N_2# in the reactants. This means that there is one mole of #N_2# required in the balanced equation.

There is a 2 coefficient in front of the #NH_3# in the products.

This is a 1:2 or 2:1 ratio. Since the desired outcome is #NH_3# put the 2 on top and the 1 on the bottom

# 6 (N_2) xx 2/1 = NH_3#

# 6 xx 2 = 12 (NH_3)#

Mar 15, 2017

You need 6 moles of #N_2# to produce 12 moles of #NH_3#.

Explanation:

The coefficients in a chemical reaction give the molar ratios of reactants and products in that reaction. You can read the above reaction (The Haber process) as saying "For every 1 mol of #N_2#, 3 moles of #H_2# will react and 2 moles of #NH_3# will be produced." So, if our ratio of #N_2# to #NH_3# is 1:2, and we need to produce 12 moles of #NH_3#, then we will need half as many moles of #N_2#, or 6 moles.