Question

Ketoacidosis is relieved by rapid breathing, which converts hydrogen carbonate ions and hydrogen ions in the blood to gaseous carbon dioxide and water, as shown in this equation. $$ \mathrm{H}^{+}+\mathrm{HCO}_{3}^{-} \longrightarrow \mathrm{H}_{2} \mathrm{CO}_{3} \longrightarrow \mathrm{H}_{2} \mathrm{O}+\mathrm{CO}_{2}(\text { Exhaled }) $$ (a) Assuming that these reactions can go in either direction, how does a state of acidosis help to increase the generation of carbon dioxide? (b) What principle describes the effect of added reactants and products on an equilibrium?

Short answer

(a) Acidosis increases \( \mathrm{H}^+ \) ions, enhancing \( \mathrm{CO}_2 \) generation. (b) This is explained by Le Chatelier's Principle.

Step-by-step solution

Analyzing the Reaction

The given chemical reaction involves hydrogen ions \( \mathrm{H}^{+} \) and hydrogen carbonate ions \( \mathrm{HCO}_{3}^{-} \) converting to carbonic acid \( \mathrm{H}_2 \mathrm{CO}_3 \), which then decomposes into water \( \mathrm{H}_2\mathrm{O} \) and carbon dioxide \( \mathrm{CO}_2 \). This is an equilibrium reaction capable of proceeding forward or backward.

Understanding the Effect of Acidosis

In a state of acidosis, there is an excess of \( \mathrm{H}^+ \) ions in the blood. According to Le Chatelier's Principle, when the concentration of a reactant is increased, the equilibrium will shift to oppose the change, in this case, generating more \( \mathrm{H}_2\mathrm{CO}_3 \) that decomposes into \( \mathrm{CO}_2 \) and \( \mathrm{H}_2\mathrm{O} \), thus increasing the production of carbon dioxide.

Applying Le Chatelier's Principle

Le Chatelier's Principle states that if a system at equilibrium experiences a change in concentration, temperature, volume, or pressure, the equilibrium will shift in a direction that counteracts the change. In this reaction, adding more \( \mathrm{H}^+ \) (as occurs in acidosis) causes the equilibrium to favor the forward reaction, increasing \( \mathrm{CO}_2 \) production.

Conclusion

Acidosis increases \( \mathrm{H}^+ \) concentration, driving the reaction toward carbon dioxide production to restore equilibrium. Le Chatelier's Principle explains how equilibrium responds to changes in reactant and product concentrations.

Key concepts

Le Chatelier's Principle

When a system in chemical equilibrium is disturbed by changes in concentration, temperature, or pressure, the system will adjust to reduce the effect of the disturbance. This is known as Le Chatelier's Principle. For example, in the case of ketoacidosis, where blood becomes too acidic, there is an excess of hydrogen ions \( \mathrm{H}^{+} \).
According to Le Chatelier's Principle, the equilibrium reaction:
\[ \mathrm{H}^{+} + \mathrm{HCO}_{3}^{-} \rightarrow \mathrm{H}_{2} \mathrm{CO}_{3} \rightarrow \mathrm{H}_{2} \mathrm{O} + \mathrm{CO}_{2} \]
will react to counteract this increase in \( \mathrm{H}^{+} \) ions. The extra hydrogen ions push the reaction forward to create more water and carbon dioxide. As a result, more carbon dioxide is produced and can be exhaled, helping to relieve the excess acidity.Le Chatelier's Principle provides a straightforward way to predict how a reaction will shift in response to changes and is vital for understanding chemical equilibrium in biological processes like blood pH management.

Acid-base reactions

Acid-base reactions involve the transfer of protons (\(\mathrm{H}^{+}\) ions) between reactants. In the context of ketoacidosis, which affects your blood's pH balance, these reactions can become life-saving mechanisms. An excess of acidic \(\mathrm{H}^{+}\) ions in the bloodstream is harmful, as it lowers the pH.
To restore balance, the blood relies on the following equilibrium reaction:
\[ \mathrm{H}^{+} + \mathrm{HCO}_{3}^{-} \rightarrow \mathrm{H}_{2} \mathrm{CO}_{3} \rightarrow \mathrm{H}_{2} \mathrm{O} + \mathrm{CO}_{2} \]
Here, \(\mathrm{HCO}_{3}^{-}\) acts as a base by accepting \(\mathrm{H}^{+}\) ions, forming carbonic acid \(\mathrm{H}_{2}\mathrm{CO}_{3}\).This newly-formed carbonic acid then breaks down into water and carbon dioxide, which is then exhaled. The dynamic nature of acid-base reactions helps the body adjust quickly to maintain pH balance. These processes are critical in managing conditions of increased acidity, such as acidosis.

Ketoacidosis

Ketoacidosis is a serious condition where excessive \(\mathrm{H}^{+}\) ions in the blood lead to dangerously low pH levels. It frequently occurs in people with diabetes when ketones build up in the body. The body's response involves rapid breathing to get rid of carbon dioxide, thus affecting the body's acid-base balance.
The reaction:
\[ \mathrm{H}^{+} + \mathrm{HCO}_{3}^{-} \rightarrow \mathrm{H}_{2} \mathrm{CO}_{3} \rightarrow \mathrm{H}_{2} \mathrm{O} + \mathrm{CO}_{2} \]
plays a crucial role in offsetting acidosis. As \(\mathrm{CO}_{2}\) levels in the blood decrease due to rapid breathing, the reaction is pushed to produce more \(\mathrm{CO}_{2}\) from the excess \(\mathrm{H}^{+}\), temporarily reducing acidity.Ketoacidosis requires urgent medical assessment. However, understanding this natural buffering mechanism illuminates how the body prioritizes balance, particularly through breathing adjustments that align with the principles of chemical equilibrium.