If the heat of combustion of carbon monoxide (CO) is −283.0 kJmole, how many grams of carbon monoxide must combust in order to release 2,500.kJ of energy?

247.4 g

Explanation:

Let's consider the thermochemical equation for the combustion of carbon monoxide.

CO(g) + 0.5 O₂(g) ⇒ CO₂(g)    ΔH°c = -283.0 kJ/mol

The moles of carbon monoxide required to release 2500 kJ (-2500 kJ) are:

-2500 kJ × (1 mol CO/-283.0 kJ) = 8.834 mol CO

The molar mass of CO is 28.01 g/mol. The mass corresponding to 8.834 moles of CO is:

8.834 mol × 28.01 g/mol = 247.4 g