Answer
7.81 L
Work Step by Step
We start with the gas law
PV = nRT
Since we have a fixed quantity, we know that n is constant and R is the gas constant so we have:
21C and 752 torr occupies 5.12L. First we convert the 21C to K by adding 273, which is 294 K.
R is 0.0821 L*atm/mol K
so we convert the 752 torr to atm. This is:
752 torr * (1atm/ 760 torr) = 0.989 atm
Then we find the number of moles:
n = PV/RT = (0.989 atm) * (5.12L) / (0.0821 * 294K) = 0.2099 moles
When the temperature is increased to 175 C (175 + 273 = 448 K) we have:
V = nRT / P = 0.2099 moles * 0.0821 * 448K / 0.989atm = 7.81 L