A fixed quantity of gas at 25°C exhibits a pressure of 722 torr and occupies a volume of 5.11 L.?

Question

(a) Use Boyle's law to calculate the volume the gas will occupy if the pressure is increased to 1.77 atm while the temperature is held constant.
______________________ Liters


(b) Use Charles's law to calculate the volume the gas will occupy if the temperature is increased to 167°C while the pressure is held constant.
_________________________ Liters

Answer 1

Two ways:

1) Use PV = nRT, you know P,V,T from Q; find n

Then for (a) and (b), use it again. You know n from above, P and T from Q., V is your unknown.

2) Use P1V1/T1 = P2V2/T2 (true because PV/T = nR, and n hasn't changed)

Both ways work. Watch units; if R is in L atm mol-1 K-1, V must be in L, P must be converted to atm., and of course T must be in K, as in all chemical calculations.