In an experiment demonstrating the evolution of oxygen in Hydrilla , sodium bicarbonate is added to water in the experiment set-up . What would happen if all other conditions are favourable ?

Options

A. Amount of oxygen evolved decreases as the availability of carbondioxide increases
B. Amount of oxygen evolved increases as carbondioxide in water is absorbed by sodium bicarbonate
C. Amount of oxygen evolved decreases as carbondioxide in water is absorbed by sodium bicarbonate
D. Amount of oxygen evolved increases as the availability of carbon dioxide increase

Answer

To solve the question regarding the effect of adding sodium bicarbonate to water in an experiment with Hydrilla, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Role of Hydrilla**:
- Hydrilla is an aquatic plant that performs photosynthesis, using carbon dioxide (CO2), water (H2O), and light (usually from the sun) to produce glucose and oxygen (O2).

2. **Identify the Function of Sodium Bicarbonate**:
- Sodium bicarbonate (NaHCO3) is added to the water. In solution, it dissociates to release bicarbonate ions (HCO3-) which can react with water to form carbonic acid (H2CO3).

3. **Carbonic Acid Decomposition**:
- The carbonic acid can decompose into carbon dioxide (CO2) and water (H2O). This reaction increases the concentration of CO2 in the water.

4. **Effect of Increased CO2 on Photosynthesis**:
- CO2 is a crucial reactant in the photosynthesis process. An increase in CO2 availability enhances the rate of photosynthesis, assuming light and temperature conditions are optimal.

5. **Oxygen Production**:
- As the rate of photosynthesis increases due to higher CO2 levels, the amount of oxygen produced as a byproduct also increases.

6. **Conclusion**:
- Therefore, if all other conditions are favorable, adding sodium bicarbonate will lead to an increase in the amount of oxygen evolved by Hydrilla.

### Final Answer:
The correct answer is: **The amount of oxygen evolved increases as the availability of carbon dioxide increases.** (Option 4)

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