Consider two reactions for the production of ethanol: C2H4(g)+H2O(g) ⟶CH3CH2OH(l) C2H6

step 1 All right, problem 64, we have two different equations that is used for producing ethanol. Okay.

Consider two reactions for the production of ethanol: ...

Consider two reactions for the production of ethanol: $$\begin{array}{l}\mathrm{C}_{2} \mathrm{H}_{4}(g)+\mathrm{H}_{2} \mathrm{O}(g) \longrightarrow \mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{OH}(l) \\ \mathrm{C}_{2} \mathrm{H}_{6}(g)+\mathrm{H}_{2} \mathrm{O}(g) \longrightarrow \mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{OH}(l)+\mathrm{H}_{2}(g) \end{array}$$ Which would be the more thermodynamically feasible at standard conditions? Why?

Consider two reactions for the production of ethanol:
$$\begin{array}{l}\mathrm{C}_{2} \mathrm{H}_{4}(g)+\mathrm{H}_{2} \mathrm{O}(g) \longrightarrow \mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{OH}(l) \\
\mathrm{C}_{2} \mathrm{H}_{6}(g)+\mathrm{H}_{2} \mathrm{O}(g) \longrightarrow \mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{OH}(l)+\mathrm{H}_{2}(g)
\end{array}$$
Which would be the more thermodynamically feasible at standard conditions? Why?

Key Concepts

Gibbs Free Energy

Gibbs free energy (?G) is the thermodynamic potential that determines the spontaneity of a chemical reaction at constant temperature and pressure. A reaction is considered thermodynamically feasible or spontaneous if its ?G is negative under standard conditions, meaning that the energy released by the reaction exceeds the energy required. This concept helps compare reactions by considering both enthalpy (heat exchange) and entropy (disorder) changes.

Enthalpy

Enthalpy (?H) is a measure of the total heat content in a chemical reaction. Exothermic reactions release heat (negative ?H), which often favors spontaneity. In assessing the feasibility of a reaction, examining the enthalpy provides insight into how strongly bonds are formed or broken, influencing the stability of products compared to reactants.

Entropy

Entropy (?S) quantifies the degree of disorder or randomness in a system. Chemical reactions that lead to an increase in entropy tend to be more favorable, particularly when the temperature is high. However, even when a reaction produces a decrease in entropy, a strongly exothermic change in enthalpy can still result in an overall negative ?G, making the reaction spontaneous.

Reaction Mechanism and Bond Breaking/Forming

The specific chemical changes, including the breaking of bonds and formation of new ones, are crucial to determining the overall energy change of a reaction. In the given reactions, the conversion of unsaturated bonds in the starting hydrocarbon or the dehydrogenation process involves different bond energies, directly affecting the reaction's enthalpy and overall thermodynamic favorability.

Transcript

Please give Ace some feedback