Which of the following is the correct chemical formula for phosphoric acid?

• A. H3PO3
• B. HPO4
• C. H2PO4
• D. H3PO4

Answer: (D)

Verified step by step guidance

1. Recall that phosphoric acid is a common oxyacid of phosphorus, and its chemical formula is based on the number of hydrogen (H), phosphorus (P), and oxygen (O) atoms it contains.
2. Understand that the general formula for phosphoric acid includes three hydrogen atoms, one phosphorus atom, and four oxygen atoms, which corresponds to the formula \(\mathrm{H_3PO_4}\).
3. Compare the given options to the known formula: \(\mathrm{H_3PO_3}\) is phosphorous acid, not phosphoric acid; \(\mathrm{HPO_4}\) is not a standard acid formula; \(\mathrm{H_2PO_4}\) represents the dihydrogen phosphate ion, not the acid itself.
4. Confirm that the correct formula for phosphoric acid is \(\mathrm{H_3PO_4}\), which matches the known chemical structure of the acid with three acidic hydrogens and one phosphate group.
5. Therefore, identify \(\mathrm{H_3PO_4}\) as the correct chemical formula for phosphoric acid among the options provided.