# Question #717bc

Jun 7, 2015

Avogrado's law investigates the relationship between moles and volume. It states that the number of particles in a gas at constant temperature and pressure is directly proportional to the volume of the gas. This means that it's a direct relationship.

In terms of formula, you have

${V}_{1} / {n}_{1} = {V}_{2} / {n}_{2}$

If you cross multiply this relationship, you get

${V}_{2} \cdot {n}_{1} = {V}_{1} \cdot {n}_{2}$

Divide both sides by ${V}_{1} \cdot {V}_{2}$ to get

$\frac{\cancel{{V}_{2}}}{{V}_{1} \cdot \cancel{{V}_{2}}} \cdot {n}_{1} = {n}_{2} \cdot \frac{\cancel{{V}_{1}}}{\cancel{{V}_{1}} \cdot {V}_{2}}$

You'll end up with

${n}_{1} / {V}_{1} = {n}_{2} / {V}_{2}$

It will be helpful if you could post the video for us to have a clear idea on what's happening!