A tank contains 11.8 g of chlorine gas (Cl2) at a temperature of 87 °C and an absolute pressure of 5.40 × 105 Pa. The mass per mole of Cl2 is 70.9 g/mol. (a) Determine the volume of the tank. (b) Later, the temperature of the tank has dropped to 27 °C and, due to a leak, the pressure has dropped to 3.20 × 105 Pa. How many grams of chlorine gas have leaked out of the tank?

My answer for part A is correct, but I can't seem to get B right.

A) V= 9.146e-4 m^3

Here's the work I did for part B:

11.8 g - (3.20e5 Pa) (9.146e-4 m^3)

----------------------------------------- X 70.9 g

(8.314 J/mol K ) (273 +27)

11.8 g - 8.31947g= 3.481 g

My answer is 3.481 g, and I'm still wrong. Any ideas anyone? Please and thank you!