[dlivasy]

Hi All,
 I really need some help with this question

A tank of 0.1-m3 volume contains air at 25oC and 101.33 kPa. The tank is connected to a compressed-air line which supplies air at the constant conditions of 45oC and 1,500 kPa. A valve in the line is cracked so that air flows slowly into the tank until the pressure equals the line pressure. If the process occurs slowly enough that the temperature in the tank remains at 25oC, how much heat is lost from the tank? Assume air to be an ideal gas for which CP = (7/2) R.

I think i have the beginning right

Nin=Nfin,1+Nfin,2

but other than that I am lost
any help would be appreciated