Marshall's acid `overset(H_(2)O) to A+B`
`Aoverset(H_(2)O)toB+C`
If P and Q represent maximum number of atoms that can lie in a plane of compound A and C respectively. Then, find out value of (P-Q).

Explanation

To solve the problem step by step, let's break down the reactions and analyze the compounds involved:

### Step 1: Identify Marshall's Acid
Marshall's acid is chemically known as peroxydisulfuric acid, which has the formula H₂S₂O₈.

### Step 2: Reaction of Marshall's Acid with Water
When Marshall's acid reacts with water, it produces two compounds, A and B. The reaction can be represented as:
\[ \text{H}_2\text{S}_2\text{O}_8 + \text{H}_2\text{O} \rightarrow \text{A} + \text{B} \]

From the video transcript, we find that:
- A = H₂SO₅ (peroxymonosulfuric acid)
- B = H₂SO₄ (sulfuric acid)

### Step 3: Reaction of Compound A with Water
Next, we react compound A (H₂SO₅) with water:
\[ \text{A} + \text{H}_2\text{O} \rightarrow \text{B} + \text{C} \]

From the transcript, we know:
- B = H₂SO₄ (sulfuric acid)
- C = H₂O₂ (hydrogen peroxide)

### Step 4: Determine the Structures of Compounds A and C
Now, we need to draw the structures of A (H₂SO₅) and C (H₂O₂) to find the maximum number of atoms that can lie in a plane.

1. **Structure of H₂SO₅ (A)**:
- The structure can be represented as:
```
O
||
HO-S-O-O-H
||
O
```
- In this structure, we can see that there are 5 atoms that can lie in the same plane: S, O, O, H, and O.

2. **Structure of H₂O₂ (C)**:
- The structure can be represented as:
```
H-O-O-H
```
- In this structure, there are 3 atoms that can lie in the same plane: O, O, and H.

### Step 5: Calculate P and Q
- Let P be the maximum number of atoms that can lie in the plane of compound A (H₂SO₅). From the structure, P = 5.
- Let Q be the maximum number of atoms that can lie in the plane of compound C (H₂O₂). From the structure, Q = 3.

### Step 6: Find P - Q
Now we can calculate:
\[ P - Q = 5 - 3 = 2 \]

### Final Answer
Thus, the value of \( P - Q \) is **2**.

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