# A container has a volume of 3 L and holds 9 mol of gas. If the container is expanded such that its new volume is 36 L, how many moles of gas must be injected into the container to maintain a constant temperature and pressure?

Mar 31, 2017

The number of moles injected is $= 99 m o l$

#### Explanation:

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

${V}_{1} = 3 L$

${n}_{1} = 9 m o l$

${V}_{2} = 36 L$

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

$= \frac{36}{3} \cdot 9 = 108 m o l$

Number of moles to be injected is $= 108 - 9 = 99 m o l$