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 known elements
- Magnesium (Mg) typically has an oxidation state of \( +2 \).
- Oxygen (O) typically has an oxidation state of \( -2 \).

### Step 2: Write the formula for the compound
The formula of the compound is \( \text{Mg}_2\text{P}_2\text{O}_7 \).

### Step 3: Set up the equation for the sum of oxidation states
Let the oxidation state of phosphorus (P) be \( x \). The total oxidation states in the compound must equal zero since it is a neutral compound.

### Step 4: Calculate the contribution from magnesium and oxygen
- There are 2 magnesium atoms contributing \( 2 \times (+2) = +4 \).
- There are 7 oxygen atoms contributing \( 7 \times (-2) = -14 \).

### Step 5: Set up the equation
The equation for the sum of oxidation states can be written as:
\[ 2(+2) + 2(x) + 7(-2) = 0 \]
This simplifies to:
\[ 4 + 2x - 14 = 0 \]

### Step 6: Solve for \( x \)
Now, we can solve the equation:
\[ 4 + 2x - 14 = 0 \]
\[ 2x - 10 = 0 \]
\[ 2x = 10 \]
\[ x = 5 \]

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

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