`Cr_(2)O_(7)^(2-)+H^(+)+SO_(3)^(2-) to Cr^(3+)(aq.)+SO_(4)^(2-)`

Options

A. For disproportionation reaction.
B. For comproportionation reaction.
C. For either intermolecular redox reaction or displacement reaction
D. For either thermal combination redox reaction or thermal decomposition redox reaction.

Answer

To solve the given reaction \( \text{Cr}_2\text{O}_7^{2-} + \text{H}^+ + \text{SO}_3^{2-} \rightarrow \text{Cr}^{3+} + \text{SO}_4^{2-} \), we will follow these steps:

### Step 1: Determine Oxidation States
First, we need to determine the oxidation states of each element in the reactants and products.

1. **Chromium in \( \text{Cr}_2\text{O}_7^{2-} \)**:
- Let the oxidation state of Cr be \( x \).
- The equation becomes: \( 2x + 7(-2) = -2 \)
- Simplifying gives: \( 2x - 14 = -2 \) → \( 2x = 12 \) → \( x = +6 \)

2. **Sulfur in \( \text{SO}_3^{2-} \)**:
- Let the oxidation state of S be \( y \).
- The equation becomes: \( y + 3(-2) = -2 \)
- Simplifying gives: \( y - 6 = -2 \) → \( y = +4 \)

3. **Chromium in \( \text{Cr}^{3+} \)**:
- The oxidation state is \( +3 \).

4. **Sulfur in \( \text{SO}_4^{2-} \)**:
- Let the oxidation state of S be \( z \).
- The equation becomes: \( z + 4(-2) = -2 \)
- Simplifying gives: \( z - 8 = -2 \) → \( z = +6 \)

### Step 2: Identify Changes in Oxidation States
Now we can summarize the changes in oxidation states:
- Chromium: \( +6 \) in \( \text{Cr}_2\text{O}_7^{2-} \) to \( +3 \) in \( \text{Cr}^{3+} \) (Reduction)
- Sulfur: \( +4 \) in \( \text{SO}_3^{2-} \) to \( +6 \) in \( \text{SO}_4^{2-} \) (Oxidation)

### Step 3: Classify the Reaction
Since there is a decrease in oxidation state for chromium (reduction) and an increase in oxidation state for sulfur (oxidation), this reaction is classified as a **redox reaction**.

### Step 4: Determine the Type of Redox Reaction
This redox reaction involves two different species undergoing oxidation and reduction, making it an **intermolecular redox reaction**.

### Conclusion
The final classification of the reaction is:
- **Type of Reaction**: Intermolecular Redox Reaction