The oxidation number of `P` in `Mg_(2)P_(2)O_(7)` is

Options

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

Explanation

To determine the oxidation number of phosphorus (P) in the compound \( \text{Mg}_2\text{P}_2\text{O}_7 \), we can follow these steps:

### Step 1: Identify the oxidation states of the other elements
- Magnesium (Mg) typically has an oxidation state of \( +2 \).
- Oxygen (O) typically has an oxidation state of \( -2 \).

### Step 2: Set up the equation based on the oxidation states
Let \( x \) be the oxidation number of phosphorus (P). The compound \( \text{Mg}_2\text{P}_2\text{O}_7 \) is neutral, so the sum of the oxidation numbers must equal zero.

The contribution to the total oxidation number from each element in the compound can be expressed as follows:
- For magnesium: \( 2 \times (+2) = +4 \)
- For phosphorus: \( 2 \times x \)
- For oxygen: \( 7 \times (-2) = -14 \)

### Step 3: Write the equation
Now we can set up the equation based on the total oxidation number:
\[ (+4) + (2x) + (-14) = 0 \]

### Step 4: Simplify the equation
Combine the constants:
\[ 2x - 10 = 0 \]

### Step 5: Solve for \( x \)
Rearranging the equation gives:
\[ 2x = 10 \]
\[ x = 5 \]

### Conclusion
The oxidation number of phosphorus (P) in \( \text{Mg}_2\text{P}_2\text{O}_7 \) is \( +5 \).