What happen when(i) a small amount of `KMnO_(4)` is added to concentrated `H_(2)SO_(4)` (ii) an excess amount of `KMnO_(4)` is added to concentrated `H_(2)SO_(4)` solution.

Answer

To answer the question about what happens when a small amount of KMnO4 is added to concentrated H2SO4 and when an excess amount of KMnO4 is added to concentrated H2SO4, we can break it down into two parts.

### Part (i): Small Amount of KMnO4 Added to Concentrated H2SO4

1. **Reaction Setup**: When a small amount of potassium permanganate (KMnO4) is added to concentrated sulfuric acid (H2SO4), a chemical reaction occurs.

2. **Products Formed**: The main products of this reaction are manganese heptoxide (Mn2O7), potassium bisulfate (KHSO4), and water (H2O).

3. **Balanced Reaction**: The balanced chemical equation for this reaction can be written as:
\[ 2 \text{KMnO}_4 + 2 \text{H}_2\text{SO}_4 \rightarrow \text{Mn}_2\text{O}_7 + 2 \text{KHSO}_4 + 2 \text{H}_2\text{O} \]

4. **Characteristics of Products**: Manganese heptoxide (Mn2O7) is a green oily substance that is highly explosive in nature, which is why this reaction is not typically performed in a laboratory setting.

### Part (ii): Excess Amount of KMnO4 Added to Concentrated H2SO4

1. **Reaction Setup**: When an excess amount of KMnO4 is added to concentrated H2SO4, a different set of products is formed.

2. **Products Formed**: The products of this reaction include potassium ions (K+), manganese trioxide (MnO3), bisulfate ions (HSO4-), and hydronium ions (H3O+).

3. **Balanced Reaction**: The balanced chemical equation for this reaction can be represented as:
\[ 3 \text{KMnO}_4 + 3 \text{H}_2\text{SO}_4 \rightarrow 3 \text{K}^+ + 3 \text{HSO}_4^- + \text{MnO}_3 + 3 \text{H}_3\text{O}^+ \]

4. **Characteristics of Products**: Manganese trioxide (MnO3) is also green in color, and the reaction produces hydronium ions, which contribute to the acidic nature of the solution.

### Summary of Reactions:
- **Small Amount of KMnO4**:
- Produces Mn2O7 (highly explosive), KHSO4, and H2O.

- **Excess KMnO4**:
- Produces K+, MnO3 (green), HSO4-, and H3O+.