Question

What is an example of a Boyle's law practice problem?

Answer 1

Boyle's Law, a principle that describes the relationship between the pressure and volume of a gas. According to this law, the pressure exerted by a gas held at a constant temperature varies inversely with the volume of the gas. For example, if the volume is halved, the pressure is doubled; and if the volume is doubled, the pressure is halved. The reason for this effect is that a gas is made up of loosely spaced molecules moving at random. If a gas is compressed in a container, these molecules are pushed together; thus, the gas occupies less volume. The molecules, having less space in which to move, hit the walls of the container more frequently and thus exert an increased pressure.

Stated as a formula, Boyle's Law reads:

`V_1`/ `V_2`= `P_2`/ `P_1` (at constant temperature)

where `V_1` equals the original volume, `V_2` equals the new volume, `P_1` the original pressure, and `P_2` the new pressure.

An unknown gas has an initial pressure of 150 kPa and a volume of 1 L. If the volume is increased to 1.5 L, what will the pressure be now?
`V_1` = 1L `P_1` = 150 kPa
`V_2`= 1.5 L `P_2` = ?

1L/ 1.5 L = `P_2` / 150 kPa

`P_2` = 150 kPa x 1 L / 1.5 L

`P_2` = 100 kPa.