Question

when placed into water, which formula represents phosphoric acid?
hpo
h₂po₂
h₃po₃
h₃po₄

Explanation:

Phosphoric acid (also known as orthophosphoric acid) has the chemical formula \( \text{H}_3\text{PO}_4 \). Let's analyze the other options:

• \( \text{HPO} \): This is not a valid or recognized formula for phosphoric acid (or a common oxyacid of phosphorus in the context of this question).
• \( \text{H}_2\text{PO}_2 \): This is the formula for hypophosphorous acid, not phosphoric acid.
• \( \text{H}_3\text{PO}_3 \): This is the formula for phosphorous acid, which is different from phosphoric acid (note the different number of oxygen atoms and the oxidation state of phosphorus).
• \( \text{H}_3\text{PO}_4 \): This is the correct formula for phosphoric acid, consisting of three hydrogen atoms, one phosphorus atom, and four oxygen atoms.

Answer:

D. \( \text{H}_3\text{PO}_4 \)