Question

Which of the following is the molecular formula of Orthophosphoric acid?

• A. \( \text{H}_3\text{PO}_3 \)
• B. \( \text{H}_3\text{PO}_4 \)
• C. \( \text{HPO}_3 \)
• D. \( \text{H}_4\text{P}_2\text{O}_7 \)

Hint:

Orthophosphoric acid is \( \text{H}_3\text{PO}_4 \). It is a triprotic acid, meaning it can donate three protons in a chemical reaction.

Answer 1

The Correct Option is B

Step 1: Understanding the formula of Orthophosphoric acid.
Orthophosphoric acid, also known as phosphoric acid, is a mineral acid with the chemical formula \( \text{H}_3\text{PO}_4 \). It contains three hydrogen atoms, one phosphorus atom, and four oxygen atoms. Step 2: Analysis of options.
(A) \( \text{H}_3\text{PO}_3 \): This is the formula of phosphorous acid, not orthophosphoric acid.
(B) \( \text{H}_3\text{PO}_4 \): Correct — This is the molecular formula of orthophosphoric acid.
(C) \( \text{HPO}_3 \): This formula represents metaphosphoric acid, not orthophosphoric acid.
(D) \( \text{H}_4\text{P}_2\text{O}_7 \): This is the formula for pyrophosphoric acid, not orthophosphoric acid.
Step 3: Conclusion.
The correct answer is (B) because \( \text{H}_3\text{PO}_4 \) is the molecular formula of orthophosphoric acid.