Question

c₂h₅oh + 3o₂ → 2co₂ + 3h₂o + 1367 kj
what is the ratio between ethanol and energy of the reaction?
? mole c₂h₅oh
——————
-□ kj
fill in the green blank.

Explanation:

Step1: Analyze the reaction equation

The given reaction is $\ce{C_{2}H_{5}OH + 3O_{2} -> 2CO_{2} + 3H_{2}O + 1367\space kJ}$. From this equation, we can see that 1 mole of $\ce{C_{2}H_{5}OH}$ (ethanol) reacts to produce 1367 kJ of energy (the negative sign indicates that energy is released, so it's an exothermic reaction).

Step2: Determine the ratio

We need to find the ratio of moles of ethanol to the energy released. From the stoichiometry of the reaction, 1 mole of ethanol is associated with 1367 kJ of energy released. So the number of moles of ethanol in the numerator of the ratio should be 1, because 1 mole of $\ce{C_{2}H_{5}OH}$ produces 1367 kJ of energy.

Answer:

1