The equation for the combustion of 2 mol of butane can be written

2C₄H₁₀(g) + O₂(g) → 8CO₂(g) + 10H₂O(g); ∆H < O

Which of the following produces the least heat?

a. Burning 1 mol of butane.

b. Reacting 1 mol of oxygen with excess butane.

c. Burning enough butane to produce 1 mol of carbon dioxide.

d. Burning enough butane to produce 1 mol of water.

e. All of the above reactions (a, b, c, and d) produce the same amount of heat.