Question

What is the oxidation state of Phosphorus in \( H_3PO_4 \)?

• A. +3
• B. +5
• C. +1
• D. +7

Hint:

To find oxidation states in neutral molecules, remember:
Sum of oxidation numbers = 0.

Answer 1

The Correct Option is B

Concept:
The oxidation state (or oxidation number) of an element represents the hypothetical charge it would have if all bonds were completely ionic. In a compound, the sum of oxidation states of all atoms must equal the overall charge of the molecule. For neutral molecules, the total oxidation state equals zero.

Step 1: Assign known oxidation states
In \(H_3PO_4\):
• Hydrogen generally has an oxidation state of \(+1\).
• Oxygen generally has an oxidation state of \(-2\).

Step 2: Let the oxidation state of phosphorus be \(x\)
\[ 3(+1) + x + 4(-2) = 0 \]

Step 3: Solve the equation \[ 3 + x - 8 = 0 \] \[ x - 5 = 0 \] \[ x = +5 \] Conclusion:
The oxidation state of phosphorus in \(H_3PO_4\) is \(\mathbf{+5}\).