A sample of gas has a volume of 400.mL at STP.What will be its volume at 20.0^°C and700.torr?

Question

Quizplus · Accepted Answer

Using the combined gas law:

(P1V1)/(T1) = (P2V2)/(T2)

P1 = 1 atm (STP) 
V1 = 400 mL 
T1 = 273 K (STP)

P2 = 700 torr 
T2 = 20.0°C = 293 K

Converting units: 
700 torr = 0.921 atm 
20.0°C = 293 K

Substituting values:

(1 atm)(400 mL)/(273 K) = (0.921 atm)(V2)/(293 K)

V2 = (1 atm)(400 mL)(293 K)/(273 K)(0.921 atm) 
V2 = 465.9 mL ≈ 466 mL

Therefore, the answer is A).

A Sample of Gas Has a Volume of 400