Arigid tank contains 10 kg of air at 137 kpa (abs) and 21°c. more air is added to the tank until the pressure and temperature rise to 242 kpa (abs) and 32°c, respectively. determine the amount of air added to the tank. [r-0.287 kj/kg k]

Ahe-xe mixture containing a 0.75 mole fraction of helium is used for cooling electronics in an avionics application. at a temperature of 300 k and atmospheric pressure, calculate the mass fraction of helium and the mass density, molar concentration and molecular weight of the mixture. if the cooling capacity is 10 l, what is the mass of the coolant?