Carbon dioxide (CO₂) fills a closed, rigid tank fitted with a paddle wheel, initially at 80°F, 30 lb/in2, and a volume of 1.6 ft3. The gas is stirred until its temperature is 500°F. During this process heat transfer from the gas to its surroundings occurs in an amount 2.6 Btu. Assume ideal gas behavior, but do not assume constant specific heats. Kinetic and potential energy effects can be ignored. Determine the mass of the carbon dioxide, in lb, and the work, in Btu.

Carbon dioxide (CO₂) fills a closed, rigid tank fitted with a paddle wheel, initially at 80°F, 30 lb/in2, and a volume of 1.6 ft3. The gas is stirred until its temperature is 500°F. During this process heat transfer from the gas to its surroundings occurs in an amount 2.6 Btu. Assume ideal gas behavior, but do not assume constant specific heats. Kinetic and potential energy effects can be ignored. Determine the mass of the carbon dioxide, in lb, and the work, in Btu.