What are the oxidation states of phosphorus in the following compounds ?
`H_(3)PO_(2),H_(3)PO_(4),Mg_(2)P_(2)O_(7),PH_(3),HPO_(3)`

Options

A. `+1, +3, +3, +3, +5`
B. `+3, +3, +5, +5, +5`
C. `+1, +2, +3, +5, +5`
D. `+1, +5, +5, -3, +5`

Explanation

To determine the oxidation states of phosphorus in the given compounds, we will follow a systematic approach using the known oxidation states of hydrogen and oxygen. Here’s the step-by-step solution for each compound:

### Step 1: Determine the oxidation state of phosphorus in H₃PO₂

1. **Assign oxidation states**:
- Let the oxidation state of phosphorus be \( x \).
- The oxidation state of hydrogen (H) is +1.
- The oxidation state of oxygen (O) is -2.

2. **Set up the equation**:
\[ 3(+1) + x + 2(-2) = 0 \]
This simplifies to:
\[ 3 + x - 4 = 0 \]
\[ x - 1 = 0 \]
\[ x = +1 \]

### Step 2: Determine the oxidation state of phosphorus in H₃PO₄

1. **Assign oxidation states**:
- Let the oxidation state of phosphorus be \( x \).

2. **Set up the equation**:
\[ 3(+1) + x + 4(-2) = 0 \]
This simplifies to:
\[ 3 + x - 8 = 0 \]
\[ x - 5 = 0 \]
\[ x = +5 \]

### Step 3: Determine the oxidation state of phosphorus in Mg₂P₂O₇

1. **Assign oxidation states**:
- Let the oxidation state of phosphorus be \( x \).
- The oxidation state of magnesium (Mg) is +2.

2. **Set up the equation**:
\[ 2(+2) + 2x + 7(-2) = 0 \]
This simplifies to:
\[ 4 + 2x - 14 = 0 \]
\[ 2x - 10 = 0 \]
\[ 2x = 10 \]
\[ x = +5 \]

### Step 4: Determine the oxidation state of phosphorus in PH₃

1. **Assign oxidation states**:
- Let the oxidation state of phosphorus be \( x \).

2. **Set up the equation**:
\[ x + 3(+1) = 0 \]
This simplifies to:
\[ x + 3 = 0 \]
\[ x = -3 \]

### Step 5: Determine the oxidation state of phosphorus in HPO₃

1. **Assign oxidation states**:
- Let the oxidation state of phosphorus be \( x \).

2. **Set up the equation**:
\[ (+1) + x + 3(-2) = 0 \]
This simplifies to:
\[ 1 + x - 6 = 0 \]
\[ x - 5 = 0 \]
\[ x = +5 \]

### Summary of Oxidation States

- **H₃PO₂**: +1
- **H₃PO₄**: +5
- **Mg₂P₂O₇**: +5
- **PH₃**: -3
- **HPO₃**: +5

### Final Answer

- The oxidation states of phosphorus in the compounds are:
- H₃PO₂: +1
- H₃PO₄: +5
- Mg₂P₂O₇: +5
- PH₃: -3
- HPO₃: +5