Question

If `32 L` of a gas at room temperature exerts a pressure of `64 kPa` on its container, what pressure will the gas exert if the container's volume changes to `24 L`?

Answer 1

The decrease in volume causes the pressure to increase to 85 kPa.

Explanation:

This is an example of Boyle's law, which states that the pressure and volume of a gas kept at constant temperature vary inversely, meaning that if the volume increases, the pressure will decrease and vice versa. The equation to use is `V_1P_1=V_2P_2`.

Given
`V_1="32 L"`
`P_1="64 kPa"`
`V_2="24 L"`

Unknown
`P_2"`

Solution
Rearrange the equation to isolate `P_2`, substitute the given values into the equation and solve.

`V_1P_1=V_2P_2`

`P_2=(V_1P_1)/(V_2)`

`P_2=((32cancel"L")xx(64"kPa"))/(24cancel"L")`

`P_2="85 kPa"` rounded to two significant figures.

As expected from Boyle's law, when the volume decreased from 32 L to 24 L, the pressure increased from 64 kPa to 85 kPa.