A rigid vessel of volume 500.0 L contains carbon dioxide (CO2) initially at a pressure of 300.0 kPa and a temperature of 300 K. Heat is added to the CO by a 2.250 kW electric heater until the final temperature reaches 1200 K. During the heat addition process 155.0 kJ of energy is lost from the CO to the environment. Assume the process can be approximated as an ideal gas. Determine the time (in seconds) the electric heater runs for assuming: i) Constant cold specific heats. ii) Constant average specific heats. iii) Variable specific heats using Table A-2c. iv) Variable specific heats using Table A-20 v) Comment briefly on the different accuracies of the results in parts i)-v). Using the result from part iv): vi) What is the final pressure? vii) Is the ideal gas assumption valid for an answer with less than 3% error?