The `pH` of blood is maintained by the balance between `H_(2)CO_(3)` and `NaHCO_(3)`. If the amount of `CO_(2)` in the blood is increased, how will it effect the `pH` of blood`?

Options

A. `pH` will remain same.
B. `pH` wil be `7`
C. `pH` will increases.
D. `pH` will decrease.

Explanation

To determine how an increase in the amount of \( CO_2 \) in the blood affects the pH of blood, we can follow these steps:

### Step 1: Understand the equilibrium reaction
The equilibrium reaction that maintains the pH of blood involves carbonic acid (\( H_2CO_3 \)) and bicarbonate (\( NaHCO_3 \)). The reaction can be represented as:
\[ H_2O + CO_2 \rightleftharpoons H^+ + HCO_3^- \]
This shows that carbon dioxide (\( CO_2 \)) reacts with water to form hydrogen ions (\( H^+ \)) and bicarbonate ions (\( HCO_3^- \)).

### Step 2: Analyze the effect of increased \( CO_2 \)
When the concentration of \( CO_2 \) in the blood increases, according to Le Chatelier's principle, the equilibrium will shift to the right to counteract the change. This means that more \( H^+ \) ions will be produced.

### Step 3: Relate \( H^+ \) concentration to pH
The pH of a solution is defined as:
\[ \text{pH} = -\log[H^+] \]
As the concentration of \( H^+ \) ions increases due to the shift in equilibrium, the pH will decrease because of the negative logarithmic relationship.

### Step 4: Body's response to decreased pH
When the pH decreases (becomes more acidic), the body has mechanisms to restore the pH to its normal level (around 7.4). One of these mechanisms is an increase in the rate of respiration. By breathing faster, the body can exhale more \( CO_2 \), which helps to reduce the concentration of \( CO_2 \) in the blood and shift the equilibrium back to the left, thus decreasing the concentration of \( H^+ \) ions.

### Step 5: Conclusion
Although the immediate effect of increased \( CO_2 \) is a decrease in pH, the body's compensatory mechanisms will work to maintain the pH around 7.4. Therefore, the overall effect is that the pH of blood is maintained despite the initial increase in \( CO_2 \).

### Final Answer:
The pH of blood will initially decrease due to increased \( CO_2 \), but the body will compensate to maintain the pH around 7.4.

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