Carbon dioxide (co2) is used in industrial and research application, and is sometimes stored at very high pressure in rigid metal tanks. consider a tank with a volume of 0.8 m^3. (a) when the tank is first deliverd to a customer on a hot summer day, the pressure is measure to be 18,000 kpa at a temperature of 35 celsius. what the mass of co2 in the tank? (b) if the temperature remains constant, when enough co2 is used such that the tank pressure is reduced in half to 9,000 kpa, what is the mass of co2 in the tank?