Difficulty: Easy
Correct Answer: orthophosphoric acid
Explanation:
Introduction / Context:Phosphorus oxyacids appear in several forms. Recognizing their empirical formulas and conventional names is important for fertilizer chemistry, water treatment, and analytical reagents.
Given Data / Assumptions:
Concept / Approach:H3PO4 is the monomeric, fully hydrated form known as orthophosphoric acid. Condensation of two orthophosphoric molecules removes water to form pyrophosphoric acid. Further condensation produces metaphosphoric (polymeric) forms. Therefore, H3PO4 must be orthophosphoric acid in standard nomenclature.
Step-by-Step Solution:
Compare formula H3PO4 with known phosphorus oxyacids.Assign the conventional name “orthophosphoric acid”.Exclude pyrophosphoric (dimer) and metaphosphoric (polymer).Confirm selection.Verification / Alternative check:Chemical handbooks universally list H3PO4 as orthophosphoric acid, used widely in fertilizers and food-grade acids.
Why Other Options Are Wrong:
Common Pitfalls:Mixing up the “ortho,” “pyro,” and “meta” prefixes; remember that condensation increases P:O ratio complexity and changes hydrogen count.
Final Answer:orthophosphoric acid
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