Oxidation number of P in `KH_(2)PO_(3)` is :-

Options

A. `-1`
B. `-3`
C. `+5`
D. `+3`

Explanation

To find the oxidation number of phosphorus (P) in the compound \( KH_2PO_3 \), we can follow these steps:

### Step 1: Identify the charges of the known elements
- Potassium (K) has a charge of +1.
- Each hydrogen (H) has a charge of +1, and since there are 2 hydrogen atoms, their total contribution is \( 2 \times +1 = +2 \).
- Oxygen (O) typically has a charge of -2. Since there are 3 oxygen atoms, their total contribution is \( 3 \times -2 = -6 \).

### Step 2: Set up the equation
Let the oxidation number of phosphorus (P) be \( x \). The overall charge of the compound is neutral (0), so we can set up the following equation based on the contributions of each element:

\[ (+1) + (+2) + x + (-6) = 0 \]

### Step 3: Simplify the equation
Combine the known values:

\[ 1 + 2 + x - 6 = 0 \]

This simplifies to:

\[ x - 3 = 0 \]

### Step 4: Solve for \( x \)
Now, solve for \( x \):

\[ x = 3 \]

### Conclusion
The oxidation number of phosphorus (P) in \( KH_2PO_3 \) is +3.