Question

PLEASE NEED HELP I got stuck! The cylinder represented above contains 2.2 Kg of a water vapor initially at a volume of 2.0m^3 and an absolute pressure of 3.0X10^5 Pa. This state is represented by point A in the PV diagram below. The molar mass of water is 18g, and the water vapor can be treated as an ideal gas.
A.) Calculate the temperature of the water vapor at point A

Answer 1

here my work. pv=nRT T=(3.0x10^3pa)(2.0m^3)/(122mol)(8.31/mol*k)
how they got (8.31/mol*k)?

Answer 2

and (122mol)