A sample of argon has a volume of 205 #cm^3# when it's temperatures is -44 degrees C. and its pressure is 712 mm of Hg. What would be the volume of the argon at STP?

1 Answer
Jul 3, 2017

We use the combined gas law, which states for a GIVEN quantity of gas..........#(P_1V_1)/T_1=(P_2V_2)/T_2#; and we eventually get #V_2~=230*cm^3#

Explanation:

#T# is always expressed as #"temperatura assoluta"#, which sets absolute zero at #0*K-=-273.15# #""^@C#. And depending on your syllabus, #STP# specifies a temperature of #273.15*K#, and a pressure of #1*atm#. And we know that #1*atm# will support a column of mercury that is #760*mm# high.........

We want #V_2=(P_1xxV_1xxT_2)/(P_2xxT_1)#.....

And already we see from the quotient we ARE going to get an answer with #"VOLUME units........"# as required.

#V_2=(712*mm*Hgxx205*cm^3xx273.15*K)/(760*mm*Hgxx229.15*K)#

#~=230*cm^3#...........