A sample of oxygen gas occupies a volume of 250. mL at 100 kPa pressure. What volume will it occupy at 200 kPa pressure?

1 Answer
May 2, 2016

Answer:

The new volume of #"O"_2"# is #"125 mL"#.

Explanation:

This is an example of Boyle's law, which states that the volume of a gas varies inversely with pressure, as long as temperature and amount are kept constant. The equation to use for this law is #P_1V_1=P_2V_2#, where #P_1# is the initial pressure, #V_1# is the initial volume, #P_2# is the final pressure, and #V_2# is the final volume.

Known
#P_1="100 kPa O"_2"#
#V_1="250 mL O"_2"#
#P_2="200 kPa O"_2"#

Unknown
#V_2="???"#

Solution
Rearrange the equation to isolate #V_2#. Substitute the known values into the equation and solve.

#P_1V_1=P_2V_2#

#V_2=(P_1V_1)/P_2#

#V_2=(100 cancel"kPa"xx250 "mL")/(200 cancel"kPa")="125 mL O"_2"#