Question

Consider the following system at equilibrium: $$ 2 \mathrm{CO}_{2}(a q) \rightleftharpoons 2 \mathrm{CO}(g)+\mathrm{O}_{2}(g) $$ Carbon monoxide is a toxic gas. Indicate whether or not each of the following would reduce the concentration of \(\mathrm{CO}\) in the system. Explain your reasoning for each. (a) add \(\mathrm{CO}_{2}\) (b) add \(\mathrm{O}_{2}\) (c) remove \(\mathrm{CO}_{2}\)

Short answer

Adding CO2 would not reduce the concentration of CO. Adding O2 would reduce the concentration of CO. Removing CO2 would not reduce the concentration of CO.

Step-by-step solution

- Understand the reaction and apply Le Chatelier's Principle

The reaction given is: \(2 CO_2(Aq)\leftrightarrow 2 CO(g) + O_2(g)\). Adding CO2 (a reactant) would push the equilibrium towards the products to minimize the change, thereby increasing the concentration of CO.

- Reasoning for adding O2

Adding O2 (a product) to the system, the system will respond by minimizing the change and shifting the equilibrium to the left. This will result in more reactants being formed and thereby decreasing the concentration of CO.

- Reasoning for removing CO2

The removal of CO2 (a reactant) from the system will shift the equilibrium towards the reactants to counteract the change, therefore increasing the concentration of CO.

Key concepts

Chemical Equilibrium

Imagine a seesaw perfectly balanced in the middle. That's what chemical equilibrium is for a chemical reaction. It's a state where the rate of the forward reaction equals the rate of the reverse reaction. No net change takes place in the concentration of reactants and products. For the given reaction, chemical equilibrium looks like this: \[2 \text{CO}_{2}(aq) \rightleftharpoons 2 \text{CO}(g) + \text{O}_{2}(g)\]At equilibrium, the amounts of carbon dioxide (\(\text{CO}_2\)), carbon monoxide (\(\text{CO}\)), and oxygen (\(\text{O}_2\)) stabilize. But keep in mind: this doesn't mean the reaction has stopped. Both forward and reverse reactions continue to occur, but at the same rate.Le Chatelier's Principle comes into play when you "disturb" this equilibrium. Adding or removing substances, or changing conditions like temperature and pressure, can "tip the seesaw." The system then shifts in the direction that opposes these changes, aiming to restore balance. Understanding how these shifts occur is key to controlling chemical processes.

• The system tries to maintain balance.
• Any change in conditions causes a shift to restore equilibrium.
• Both reactants and products are equally important at this stage.

Reaction Shifts

Think of reaction shifts like a gentle nudge that helps the system regain its balance whenever a change is made. Le Chatelier's Principle explains how these nudges happen.

• **Adding Reactants:** When you add a reactant, like \(\text{CO}_2\), the system responds by shifting towards the products. Essentially, it tries to "consume" the added reactant until a new equilibrium is established.
• **Adding Products:** Conversely, adding a product, such as \(\text{O}_2\), pushes the equilibrium back toward the reactants. This helps to "neutralize" the added product.
• **Removing Reactants or Products:** Removing a substance prompts the system to favor the side that compensates for the loss. For instance, removing \(\text{CO}_2\) will shift equilibrium toward more reactants forming.

These shifts can be visualized like a balancing act. The system naturally adjusts to minimize the disturbance, aiming to restore a state of equilibrium.

Carbon Monoxide Concentration

Carbon monoxide (CO) is an important part of our discussion, particularly because of its toxic nature. Changes in carbon monoxide concentration are directly influenced by shifts in the chemical equilibrium.When \(\text{CO}_2\) is added, as per Le Chatelier's Principle, the equilibrium shifts right, making more \(\text{CO}\). This increase in carbon monoxide can be dangerous if not controlled.On the flip side, adding \(\text{O}_2\) encourages a shift left, which reduces \(\text{CO}\) concentration. It's safer, as more reactants form, reversing the reaction to produce less toxic gas.Removing \(\text{CO}_2\) also affects \(\text{CO}\) by urging the equilibrium towards developing more \(\text{CO}_2\) initially, inadvertently boosting \(\text{CO}\)'s presence.

• Add \(\text{CO}_2\): Increases \(\text{CO}\) concentration.
• Add \(\text{O}_2\): Decreases \(\text{CO}\) concentration.
• Remove \(\text{CO}_2\): Initially can increase \(\text{CO}\) concentration.

Managing the concentration of carbon monoxide is vital in situations where its presence needs to be minimized, such as in enclosed environments or industrial applications. Keeping this toxic gas in check is essential.