Which of the following equlibrium will shift to right side on increasing the temperature

Options

A. `CO_((g))+H_(2)O_((g))hArrCO_(2(g))+H_(2(g))`
B. `2SO_(2(g))+O_(2(g))hArr2SO_(3(g))`
C. `H_(2)O_((g))hArrH_(2(g))+1/2(O_(2))_((g))`
D. `4HCl_((g))+O_(2(g))hArr2H_(2)O_((g))+2Cl_(2(g))`

Explanation

To determine which equilibrium will shift to the right side upon increasing the temperature, we need to consider the nature of the reactions involved—specifically, whether they are endothermic or exothermic.

### Step-by-Step Solution:

1. **Understand Le Chatelier's Principle**:
Le Chatelier's Principle states that if a system at equilibrium is subjected to a change in temperature, pressure, or concentration, the system will adjust to counteract that change and restore a new equilibrium.

2. **Identify Endothermic and Exothermic Reactions**:
- Endothermic reactions absorb heat. When the temperature increases, the equilibrium shifts to favor the formation of products.
- Exothermic reactions release heat. When the temperature increases, the equilibrium shifts to favor the reactants.

3. **Analyze the Given Reactions**:
We need to evaluate the reactions provided in the options. We are looking for an endothermic reaction, as it will shift to the right (towards products) when the temperature is increased.

4. **Evaluate Option 3**:
The reaction given is:
\[ H_2O (l) \rightleftharpoons H_2 (g) + \frac{1}{2} O_2 (g) \]
This reaction is known to be endothermic because it requires energy (heat) to break the bonds in water to produce hydrogen and oxygen gases.

5. **Conclusion**:
Since the reaction of water dissociating into hydrogen and oxygen is endothermic, increasing the temperature will shift the equilibrium to the right, favoring the production of hydrogen and oxygen gases.

Thus, the answer is **Option 3: \( H_2O \rightleftharpoons H_2 + \frac{1}{2} O_2 \)**.