Problem 75 - Chemistry Matter and Change

Question

Ethyl acetate \(\left(\mathrm{CH}_{3} \mathrm{COCH}_{2} \mathrm{CH}_{3}\right)\) is produced in the equilibrium system described by the following equation. $$\begin{array}{c}{\mathrm{CH}_{3} \mathrm{COOH}+\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{OH} \rightleftharpoons} \\ \quad \quad \quad \quad \quad \quad \quad \quad \quad \quad \quad \quad \quad \quad \quad {\mathrm{CH}_{3} \mathrm{COCCH}_{2} \mathrm{CH}_{3}+\mathrm{H}_{2} \mathrm{O}}\end{array}$$ Why does the removal of water result in the production of more ethyl acetate?

Step-by-Step Solution

Answer

Removing water shifts equilibrium right, increasing ethyl acetate production.

Step 1: Le Chatelier’s Principle

Le Chatelier's Principle states that if an equilibrium system is subjected to a change (in concentration, temperature, or pressure), the position of equilibrium shifts to counteract the change and re-establish equilibrium.

Step 2: Identify the System's Reaction to Water Removal

In the given reaction: \[\mathrm{CH}_{3} \mathrm{COOH} + \mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{OH} \rightleftharpoons \mathrm{CH}_{3} \mathrm{COCCH}_{2} \mathrm{CH}_{3} + \mathrm{H}_{2} \mathrm{O}\]the removal of water \(\mathrm{H}_2 \mathrm{O}\) will be detected by the system.

Step 3: Equilibrium Shift Direction

According to Le Chatelier's Principle, if water is removed, the equilibrium will shift to the right to produce more products (including water) in order to offset the loss. This will result in increased production of ethyl acetate \(\mathrm{CH}_{3} \mathrm{COCCH}_{2} \mathrm{CH}_{3}\).

Key Concepts

Le Chatelier's Principle

Le Chatelier's Principle is a foundation of chemical equilibrium understanding. It guides us on how systems adjust to changes in conditions. Imagine a peaceful pond suddenly disturbed by a stone thrown into it. The ripples you see are similar to what happens in a chemical reaction when you change certain factors. If you alter the concentration, temperature, or pressure, the system will shift to restore balance. For example, if you increase the concentration of a reactant, the system will shift toward the products to balance it out. This principle is key in predicting how an equilibrium might change when conditions are adjusted.

Equilibrium Shift

An equilibrium shift occurs when the balance of a reversible reaction is changed. Let's explore why removing water causes more ethyl acetate production in the reaction:\[\mathrm{CH}_{3} \mathrm{COOH} + \mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{OH} \rightleftharpoons \mathrm{CH}_{3} \mathrm{COCCH}_{2} \mathrm{CH}_{3} + \mathrm{H}_{2} \mathrm{O}\]When you remove water, you are changing the concentration of one product. According to Le Chatelier’s Principle, equilibrium will shift in the direction that produces more products to counteract this change. Here, it means the reaction shifts to the right, creating more ethyl acetate and water. This shift helps re-establish a new balance by producing more of what was removed, thus enhancing the formation of ethyl acetate.

Reaction Dynamics

Reaction dynamics describe how fast and in which direction a reaction proceeds under specific conditions. They determine how the reactants interact and transform into products. In equilibrium systems, reaction dynamics consider both the forward and reverse reactions. - **Forward Reaction:** Converts reactants into products. - **Reverse Reaction:** Converts products back into reactants. In the presence of a disturbance, like removing a product, the dynamics skew towards replenishing that product. If the products are removed, such that the concentration of ethyl acetate and water decreases, the forward reaction speeds up, forming more of these products. This dynamic process is integral in achieving equilibrium, where the rates of the forward and reverse reactions become equal again. Understanding these dynamics helps us predict how adjustments in reaction conditions can alter the rate and direction of chemical processes.