Question

Species acting as both Bronsted acid and base is
(a) (HSO₄)^–1 

(b) Na₂CO₃

(c) NH₃ 

(d) OH^–1.

Answer 1

(a) : According to BronstedLowry concept, a Bronsted acid is a substance which can donate a proton to any other substance and a Bronsted base is a substance which can accept a proton from any other substance.
(HSO₄ )^– can accept and donate a proton.
(HSO₄ )^– + H⁺ → H₂ SO₄
(HSO₄ )^– – H⁺ → SO₄^2–.