Question

A gas occupies a volume of 0.140 L at 35.0°C and 97.0 kPa. What is the volume of the gas at STP?

Answer 1

The volume of the gas at STP of 273.15 K and 100 kPa is 0.120 L.

Explanation:

STP currently has the values of 273.15 K and 100 kPa.

This is a question involving the combined gas law as shown below.

`V_1="0.140 L"`
`P_1="97.0 kPa"`
`T_1="35.0"^@"C"+273.15=308.15 K"`
`P_2="100 kPa"`
`T_2="273.15 K"`
`V_2="???"`

Rearrange the combined gas law to isolate `V_2`, plug in the known values, then solve.

`V_2=(P_1V_1T_2)/(T_1P_2)`

`V_2=((97.0cancel"kPa")xx(0.140"L")xx(273.15cancel"K"))/((308.15cancel"K")xx(100cancel"kPa"))="0.120 L"`