Question

A. A sample of gas in a balloon has an initial temperature of 38 ∘C and a volume of 1670 L . If the temperature changes to 72 ∘C , and there is no change of pressure or amount of gas, what is the new volume, V2, of the gas?

B. What Celsius temperature, T2, is required to change the volume of the gas sample in Part A (T1 = 38 ∘C , V1= 1670 L ) to a volume of 3340 L ? Assume no change in pressure or the amount of gas in the balloon.

Answer 1

Gas law equation can be written as

PV= nRT, n is no of moles, R is gas constant, P is pressure and T is temperature in K.

V= nRT/P

for a given mass of gas (n is constant ), When pressure is constant, nR/P is constant and the equation becomes

V =   K*T, where K= constant.

For two different conditions of volumes V1, V2 and temperatures T1, T2

V2/T2= V1/T1

V2= V1*T2/T1, = 1670*(72+273)/ (38+273)=1852.57 L

2. for the second case , V1= 1670 L, T1= 38+273= 311K, V2= 3340 L, T2 =?

T2= V2T1/V1= 3340*311/1670 =622 K, T2 expressed in deg.c= 622-273= 349 deg.c