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?

1 Answer
Sep 17, 2016

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.

http://me-mechanicalengineering.com/gas-laws/http://me-mechanicalengineering.com/gas-laws/

V_1="0.140 L"V1=0.140 L
P_1="97.0 kPa"P1=97.0 kPa
T_1="35.0"^@"C"+273.15=308.15 K"T1=35.0C+273.15=308.15K
P_2="100 kPa"P2=100 kPa
T_2="273.15 K"T2=273.15 K
V_2="???"V2=???

Rearrange the combined gas law to isolate V_2V2, plug in the known values, then solve.

V_2=(P_1V_1T_2)/(T_1P_2)V2=P1V1T2T1P2

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