Question

A container has a volume of `18 L` and holds `7 mol` of gas. If the container is compressed such that its new volume is `8 L`, how many moles of gas must be released to maintain a constant temperature and pressure?

Answer 1

`3 8/9 mol`

Explanation:

Let n moles of gas to be released .

Given
`V_1= "Initial volume of gas"=18L`

`V_2= "Final volume of gas"=8L`

`n_1= "Initial no mole of gas"=7 mol`

`n_2= "Final no.of moles of gas"=7-n`

As the temerature and pressure of two gases are same their volume should be proportional to their respective no. Of moles as we know from Avogadro's law.

So

`n_2/n_1=V_2/V_1`

`=>(7-n)/7=8/18`

`=>7-n=28/9`
`=>n=7-28/9=35/9=3 8/9mol`