Final answer:
To determine the fuel that produces the greatest amount of heat per gram, compare their heats of combustion.
Step-by-step explanation:
In order to determine which fuel produces the greatest amount of heat per gram when burned under standard conditions, we need to compare the heat of combustion of CO(g), CH4(g), and C2H2(g). The heat of combustion is a measure of the energy released when a substance is completely burned. It is calculated by subtracting the heat of formation of the products from the heat of formation of the reactants. The fuel with the highest heat of combustion per gram will produce the greatest amount of heat when burned.