Question

If `9/7 L` of a gas at room temperature exerts a pressure of `12 kPa` on its container, what pressure will the gas exert if the container's volume changes to `3/4 L`?

Answer 1

Gas will exert a pressure of `20.47kPa`

Explanation:

Pressure `P`, volume `V` and temperature `T` (in Kelvin) have the relation `PV/T=k` where `k` is a constant.

As no change in the temperature has been mentioned it is assumed to be constant at room temperature and then `P_1xxV_1=P_2xxV_2`

In the given case, `9/7` `L` of gas inside of a container exerts a pressure of `12kPa` of pressure and is at a temperature of `30^oK`. When the volume of the gas changes to `3/4` `L`, the pressure becomes `P_2`, we should have

`12xx9/7=P_2xx3/4` or `P_2=(12xx9xx4)/(3xx7)=144/7=20.47`

i.e. `P_2=20.47kPa`