Pyrolusite ore on oxidation with `KCIO_(3)//KNO_(3)` in basic medium produces dark green coloured compound `(A)`, which on electrolysis produces a purple coloured compound `(B)`. The purple coloured rhombic prisms. It shows different reactions in different mediums.
Excess of compounds (B) on heating with conc. `H_(2)SO_(4)` gives an explosive oil (C ), which on heating decomposes to gives another compound (D ) along with oxygen.
The nature of compound (C ) is `:`

Options

A. Basic
B. acidic
C. neutral
D. amphoteric

Answer

To determine the nature of compound (C) formed from the reaction of pyrolusite ore with potassium chlorate in basic medium, let's break down the problem step by step.

### Step 1: Identify the starting materials and reactions
- Pyrolusite ore is primarily composed of manganese dioxide (MnO2).
- When MnO2 is oxidized with potassium chlorate (KClO3) in a basic medium, it produces a dark green compound (A).

### Step 2: Write the reaction for the formation of compound (A)
- The reaction can be represented as:
\[ 2 \text{MnO}_2 + 2 \text{KClO}_3 \rightarrow \text{Mn}_2\text{O}_7 + 2 \text{KCl} \]
- Here, compound (A) is manganese heptoxide (Mn2O7), which is dark green in color.

### Step 3: Electrolysis of compound (A) to form compound (B)
- The dark green compound (A) undergoes electrolysis to produce a purple compound (B).
- The electrolysis of Mn2O7 yields potassium permanganate (KMnO4), which is purple in color.

### Step 4: Identify the properties of compound (B)
- Compound (B) is potassium permanganate (KMnO4), known for its purple color and rhombic prism shape.

### Step 5: Reaction of compound (B) with concentrated sulfuric acid
- When excess KMnO4 is heated with concentrated sulfuric acid (H2SO4), it produces an explosive oil (C):
\[ 2 \text{KMnO}_4 + 3 \text{H}_2\text{SO}_4 \rightarrow \text{Mn}_2\text{O}_7 + 2 \text{KHSO}_4 + 2 \text{H}_2\text{O} \]
- Here, compound (C) is manganese heptoxide (Mn2O7), which is an oily liquid.

### Step 6: Decomposition of compound (C)
- Upon heating, Mn2O7 decomposes to form manganese dioxide (MnO2) and oxygen (O2):
\[ 2 \text{Mn}_2\text{O}_7 \rightarrow 4 \text{MnO}_2 + \text{O}_2 \]

### Step 7: Determine the nature of compound (C)
- The oxidation state of manganese in Mn2O7 is +7, which indicates that it is in a high oxidation state.
- Compounds with high oxidation states are typically acidic in nature.

### Conclusion
- Therefore, the nature of compound (C) (Mn2O7) is **acidic**.