Air in a horizontal piston-cylinder assembly expands from an initial volume of 0.25 m3 to a final

Question:

Air in a horizontal piston-cylinder assembly expands from an initial volume of 0.25 m3 to a final volume of 0.5 m3 as the gas is heated for 90 seconds by an electrical resistance heater consuming 1 kW of electric power. If the atmospheric pressure is 100 kPa, determine
(a) WB.
(b) Wnet.
(c) What-if Scenario: How would the answers change if the cylinder contained oxygen instead? (0:no change; 1:increase; -1:decrease)