Question

A sample of gas has a volume of 250 c`m^3` at 28.5 °C and 95.9 kPa. What volume will the gas occupy at STP?

Answer 1

The volume of the gas at STP will be `"0.217 L"`.

Explanation:

`"STP=273.15 K and 100 kPa"`

Use the equation from the combined gas law, `(P_1V_1)/T_1=(P_2V_2)/T_2`.

Given/Known
`P_1="95.9 kPa"`
`V_1="250 cm"^3"=250 mL"xx(1 "L")/(1000 "mL")="0.250 L"`
`T_1="28.5"^"o""C"+273.15="301.7 K"`
`P_2="100 kPa"`
`T_2="273.15 K"`

Unknown
`V_2`

Equation
`(P_1V_1)/T_1=(P_2V_2)/T_2`.

Solution
Rearrange the equation to isolate `V_2` and solve.

`V_2=(P_1V_1T_2)/(T_1P_2)`

`"V"_2=((95.9 "kPa") * (0.250"L") * (273.15"K"))/((301.7"K")*(100"kPa"))="0.217 L"`