An isolated isochoric tank with a volume of 15m3, an initial temperature of 335 K, containing 2700 moles of gas loses some insulation and begins to cool to the ambient temperature. Assuming the final temperature is 298 K,

(a) Find the initial pressure of the system (in atm) assuming it is an ideal gas.

(b) Was using the ideal gas EOS for part (a) justified? Why or why not.

(c) Find the final pressure of the gas using the initial pressure from part (a) , assuming the van der Waals EOS with a = 3.948 x 10-7 m6 atm/mol2 and b = 2 x 10-4 3/.

(d) How much work was done in part (c) by the gas on the surroundings?

(e) How much heat is transferred given that the gas has a specific heat of 43.1 KJ/(Kmol K) (consider books convention in the sign of heat transfer).