4.79 A rigid tank whose

volume is 2 m3, initially

containing air at 1 bar, 295 K, is

connected by a valve to a large

vessel holding air at 6 bar, 295

K. The valve is opened only as

long as required to fill the tank

with air to a pressure of 6 bar

and a temperature of 350 K.

Assuming the ideal gas model

for the air, determine the heat

transfer between the tank

contents and the surroundings,

in kJ.