# 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?

Mar 15, 2017

Use the mole ratio of $\frac{N H 3}{N} _ 2$the ratio is 2:1 or 1:2 so it will take 6 moles of ${N}_{2}$ to make 12 moles of $N {H}_{3}$

#### 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 $N {H}_{3}$ in the products.

This is a 1:2 or 2:1 ratio. Since the desired outcome is $N {H}_{3}$ put the 2 on top and the 1 on the bottom

$6 \left({N}_{2}\right) \times \frac{2}{1} = N {H}_{3}$

$6 \times 2 = 12 \left(N {H}_{3}\right)$

Mar 15, 2017

You need 6 moles of ${N}_{2}$ to produce 12 moles of $N {H}_{3}$.

#### 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 $N {H}_{3}$ will be produced." So, if our ratio of ${N}_{2}$ to $N {H}_{3}$ is 1:2, and we need to produce 12 moles of $N {H}_{3}$, then we will need half as many moles of ${N}_{2}$, or 6 moles.