An ideal gas expands from 33.0 L to 97.0 L at a constant pressure of 1.00 atm. Then, the gas is cooled at a constant volume of 97.0 L back to its original temperature. It then contracts back to its original volume without changing temperature. Find the total heat flow, in joules, for the entire process.

The net heat flow in the whole process is zero

Explanation:

This is because in the first phase of expansion, heat Q is added to the gas that causes expansion at constant pressure. The internal energy ΔU of the gas increase and the gas does work W on its surroundings. In the cooling phase, the internal energy ΔU gained in the expansion phase is lost by cooling the gas back to it's original state (temperature) at constant volume of 93L. The exact amount of work done W is no reversed as negative work on the gas - W in the contraction phase as the gas comes back to it's original volume (the gas loses heat in cooling down to it's original volume the heat lost is equal to - W). So in effect the the total change in internal energy ΔU = 0 and total change work done W + (-W) = 0

Since the total heat Q = ΔU + W = 0 + 0 then Q = 0.