Question

Given this equation: ${N_2} + 3{H_2} \to 2N{H_3}$ , write the following molar ratios:
a) ${N_2}/{H_2}$ b) ${N_2}/N{H_3}$ and c) ${H_2}/N{H_3}$

Answer 1

Nitrogen gas combines with hydrogen gas to form ammonia. The moles of each gas can be known from the balanced chemical equation. The coefficients written below each reactant are the moles of that reactant. The ratio of the moles of two gases or two reactants gives the mole ratio of those two gases.

Complete Step By Step Answer:
Molecules are the combination of atoms. Nitrogen gas is a molecule with a molecular formula of ${N_2}$ , hydrogen gas is a molecule with a molecular formula of ${H_2}$ . Both these gases combine with each other to form a molecule known as ammonia with the molecular formula of $N{H_3}$ . There is one atom of nitrogen, and three atoms of hydrogen.
The balanced chemical equation of the combination of nitrogen and hydrogen gas to ammonia is as follows:
${N_2} + 3{H_2} \to 2N{H_3}$
Moles of a compound are nothing but the coefficients that were written below of each compound in a balanced chemical equation.
The moles of nitrogen are $1$
The moles of hydrogen are $3$
The moles of ammonia are $2$
Thus, the molar ratio of nitrogen gas, hydrogen gas, and ammonia are $1:3:2$
Molar ratio of ${N_2}/{H_2}$ is $1:3$
Mole ratio of ${N_2}/N{H_3}$ is $1:2$
Mole ratio of ${H_2}/N{H_3}$ is $3:2$ .

Note:
When a balanced chemical equation is not given, and only masses are given. Then the ratio of mass to molar mass gives the moles. From these moles and the compounds, the balanced chemical equation should be written. Based on this, the molar ratios can be written. Thus, the balanced chemical equation is necessary to determine molar ratios.