Pick out the ideal condition for `H_(2)SO_(4)` manufactured by Contact process

Options

A. Low temperature, high pressure and high concentration of reactants
B. Low temperature, low pressure and low concentration of reactants
C. High temperature, high pressure and high concentration of reactants
D. Low temperature, low pressure and high concentration of reactants

Answer

To determine the ideal conditions for the manufacture of sulfuric acid (H₂SO₄) by the Contact process, we need to analyze the key reaction involved and apply Le Chatelier's principle. Here’s a step-by-step solution:

### Step 1: Identify the Key Reaction
The main reaction in the Contact process is:
\[ \text{SO}_2(g) + \text{O}_2(g) \rightleftharpoons \text{SO}_3(g) \]
This reaction is crucial for the production of sulfuric acid.

### Step 2: Determine the Nature of the Reaction
This reaction is exothermic, meaning it releases heat. In terms of chemical equilibrium, we can represent it as:
\[ \text{SO}_2(g) + \text{O}_2(g) \rightleftharpoons \text{SO}_3(g) + \text{heat} \]

### Step 3: Apply Le Chatelier's Principle
According to Le Chatelier's principle, if we change the conditions of a reaction at equilibrium, the system will adjust to counteract that change.

- **Temperature**: Since the reaction is exothermic, lowering the temperature will favor the formation of products (SO₃). Therefore, a lower temperature is ideal. The industrial average temperature is around 720 K.

- **Pressure**: The reaction involves 2 moles of gas (SO₂ and O₂) on the reactant side and 1 mole of gas (SO₃) on the product side. Increasing the pressure will favor the side with fewer moles of gas, which is the product side in this case. Thus, high pressure is favorable, typically around 2 bar.

### Step 4: Concentration of Reactants
To maximize the production of SO₃, a high concentration of the reactants (SO₂ and O₂) is also necessary. This ensures that there are enough reactants available to shift the equilibrium towards the products.

### Conclusion
The ideal conditions for the manufacture of H₂SO₄ by the Contact process are:
- **Low Temperature**: Around 720 K
- **High Pressure**: Approximately 2 bar
- **High Concentration of Reactants**: To ensure sufficient availability of SO₂ and O₂

### Summary of Ideal Conditions
- Low Temperature (720 K)
- High Pressure (2 bar)
- High Concentration of Reactants

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