0.75 mol of argon gas is admitted to an evacuated 40 cm^{3} container at 40 C. The gas then undergoes an isochoric heating to a temperature of 500 C.

Answer 1

What is the question?
I had to look up "isochoric". It means "contant volume". During that heating process, p will increase such that it remains proportional to (absolute) T. The absolute temperature increases by a factor 773/313 = 2.47. Pressure increases by the same factor. They do not tell you the initial pressure, but you can get the pressure using

P = nRT/V

where R = 82.06 cm^3*atm/mole K

Po = 0.75*82.06*313/40 = 482 atm