If 0.3 M phosphoric acid undergoes complete neutralisation, what is its normality?
Answer and explanation
Correct answer: 0.9 N
Normality depends on the reaction and equals molarity times the acid–base n-factor. In complete neutralisation, one mole of H₃PO₄ can donate three acidic protons, so n-factor = 3. Hence N = 0.3 mol L⁻¹ × 3 = 0.9 eq L⁻¹ = 0.9 N. Thus A is correct; B counts one proton, C counts two, and D uses an excessive factor.
Frequently asked questions
What is the correct answer to this question?
0.9 N
Why is this the correct answer?
Normality depends on the reaction and equals molarity times the acid–base n-factor. In complete neutralisation, one mole of H₃PO₄ can donate three acidic protons, so n-factor = 3. Hence N = 0.3 mol L⁻¹ × 3 = 0.9 eq L⁻¹ = 0.9 N. Thus A is correct; B counts one proton, C counts two, and D uses an excessive factor.
Which subject and chapter does this question cover?
This is a Class 11 Chemistry question. Chapter: Equilibrium. Topic: Ionic equilibrium (ionization of acids and bases).
