Question

Identify the brønsted base in the forward reaction hpo2− 4 (aq) + hno3(aq) ⇀↽ no− 3 (aq) + h2po− 4 (aq). 1. h2po− 4 (aq) 2. hno3 3. hpo2− 4 4. no− 3

Answer 1

According to Bronsted theory of acid and base, an acid in a proton donor while base is a proton acceptor. Acid donates the proton to form conjugate base, while base accepts proton to form corresponding conjugate acid.

For the reaction,
hpo2− 4 (aq) + hno3(aq) ⇔ no− 3 (aq) + h2po− 4 (aq)

In above forward reaction, hno3 donotes proton to form no-3, hence no-3 is a conjugate base.