chemistry
posted by kelly .
A given mass of gas occupies a volume of 449 mL at 25°C and 740 mmHg. What will be the new volume at STP?

Use the combined gas law:
P2V2/T2= P1V1/T1
V2=P1V1T2/P2T1 
Using the gas equation,
V1=499ml; T1=25C+273K=298
P1=740mmHg
At s.t.p
P2=760mmHg; T2=273K; V2=?
V2= 499*740*273 /760*298
=445.1 ans