Which one of the following is a tribasic acid?
[amp_mcq option1=”Hydrochloric acid” option2=”Nitric acid” option3=”Sulphuric acid” option4=”Phosphoric acid” correct=”option4″]
This question was previously asked in
UPSC NDA-2 – 2018
– Monobasic acids donate one proton (e.g., HCl, HNO₃).
– Dibasic acids donate two protons (e.g., H₂SO₄, H₂CO₃).
– Tribasic acids donate three protons (e.g., H₃PO₄).
1. H₃PO₄ ⇌ H⁺ + H₂PO₄⁻
2. H₂PO₄⁻ ⇌ H⁺ + HPO₄²⁻
3. HPO₄²⁻ ⇌ H⁺ + PO₄³⁻
Hydrochloric acid (HCl) and nitric acid (HNO₃) are monobasic. Sulphuric acid (H₂SO₄) is dibasic.