Question

According to Bronsted-Lowry concept of acids and bases a conjugate acid-base pair can exist as:
Mark the option in which conjugate pair is not correctly matched.

• A. Species - $HC{O}_3^{-}$; Conjugate acid - $C{O}_3^{2-}$; Conjugate base - $H_{2}C{O}_3$
• B. Species - $HP{O}_4^{2-}$; Conjugate acid - $H_{2}P{O}_4^{-}$; Conjugate base - $P{O}_4^{3-}$
• C. Species - $N{H}_3$; Conjugate acid - $N{H}_2^{-}$; Conjugate base - $N{H}_4^{+}$
• D. Species - $H{S}^{-}$; Conjugate acid - $S^{2-}$; Conjugate base - $H_{2}S$

Answer 1

The correct option is B Species - $HP{O}_4^{2-}$; Conjugate acid - $H_{2}P{O}_4^{-}$; Conjugate base - $P{O}_4^{3-}$

Bronsted Lowry acid base conjugate pairs differ by just one proton (acid has the extra proton). bronsted lowry acids are proton donors and bronsted lowry bases are proton acceptors.

The conjugate acid of hydrogen phosphate($HP{O}_4^{2-}$) is $\left(H_{2}P{O}_4^{-}\right)$ dihydrogen phosphate ion and the conjugate base is $\left(P{O}_4^{3-}\right)$ phosphate ion.