If 0.1 mole `H_(3)PO_(x)` is completely neutralised by 5.6g KOH then select the true statement.

Options

A. (a) x=3 and given acid is diabasic
B. (b) x=4 and given acid has no P=H linkage
C. (c) x=2 and given acid does not form acid salt
D. (d) all of these

Answer

To solve the problem, we need to determine the value of \( x \) in the compound \( H_3PO_x \) based on the neutralization reaction with KOH. Here are the steps to arrive at the solution:

### Step 1: Calculate the moles of KOH
First, we need to calculate the number of moles of KOH from the given mass.

**Given:**
- Mass of KOH = 5.6 g
- Molar mass of KOH = 39 (K) + 16 (O) + 1 (H) = 56 g/mol

**Calculation:**
\[ \text{Moles of KOH} = \frac{\text{Mass}}{\text{Molar mass}} = \frac{5.6 \text{ g}}{56 \text{ g/mol}} = 0.1 \text{ moles} \]

### Step 2: Determine the possible acids
The acid \( H_3PO_x \) can take three different forms based on the value of \( x \):
1. \( H_3PO_4 \) (x = 4)
2. \( H_3PO_3 \) (x = 3)
3. \( H_3PO_2 \) (x = 2)

### Step 3: Analyze the neutralization reactions
Next, we will analyze how many moles of KOH are required for each acid:

1. **For \( H_3PO_4 \)**:
- Reaction: \( H_3PO_4 + 3 KOH \rightarrow K_3PO_4 + 3 H_2O \)
- Moles of KOH required for 0.1 moles of \( H_3PO_4 \):
\[ 0.1 \text{ moles of } H_3PO_4 \times 3 = 0.3 \text{ moles of KOH} \]

2. **For \( H_3PO_3 \)**:
- Reaction: \( H_3PO_3 + 2 KOH \rightarrow K_2HPO_3 + 2 H_2O \)
- Moles of KOH required for 0.1 moles of \( H_3PO_3 \):
\[ 0.1 \text{ moles of } H_3PO_3 \times 2 = 0.2 \text{ moles of KOH} \]

3. **For \( H_3PO_2 \)**:
- Reaction: \( H_3PO_2 + KOH \rightarrow KH_2PO_2 + H_2O \)
- Moles of KOH required for 0.1 moles of \( H_3PO_2 \):
\[ 0.1 \text{ moles of } H_3PO_2 \times 1 = 0.1 \text{ moles of KOH} \]

### Step 4: Compare required moles of KOH with available moles
- From the calculations:
- \( H_3PO_4 \) requires 0.3 moles of KOH (not possible with 0.1 moles available).
- \( H_3PO_3 \) requires 0.2 moles of KOH (not possible with 0.1 moles available).
- \( H_3PO_2 \) requires 0.1 moles of KOH (this is possible with the available moles).

### Step 5: Conclusion
Since only \( H_3PO_2 \) can react with the available 0.1 moles of KOH, we conclude that:
- \( x = 2 \) and the acid is \( H_3PO_2 \).

### Step 6: Identify the true statement
Among the given statements:
- The correct statement is: "X is equal to 2 and the given acid does not form acidic salt."