A sample of hydrogen has a volume of 1107 mL when the temperature is 101.9 degC and the pressure is 0.867 atm. What will be the volume of the gas at STP?

1 Answer
Jan 2, 2016

The combined gas law holds that for a given quantity of gas:

#(P_1V_1)/T_1 = (P_2V_2)/T_2#

Explanation:

We use an absolute scale of temperature, #0^@# #C# #=# #273# #K#.

So #V_2# #=# #(P_1T_2V_1)/(P_2T_1)# #=#

#((0.867*atm)/(0.987*atm))xx(1107*mL)xx(273*K)/(375.1*K)# #=# #??# #mL#.

The volume should reasonably decrease even though the pressure increases marginally. Note that I am perfectly justified in retaining non-standard units such as atmospheres and millilitres in that these cancel out. I must use the absolute temperature scale.