Which of the following is a conjugate acid- base pair?

Question

Which of the following is a conjugate acid- base pair?

a)all of these

b)NaF and F^-

c)None of these

d)HI and I^-

e)HNO3 and HNO2

Answer 1

Then only difference between an acid and base in a conjugate pair is H⁺ ion. Specifically, the acid contains the H⁺ and after donation converts to its conjugate base. Likewise, when a prospective base gains an H⁺ ion, it converts into its conjugate acid.

The only answer that reflects the above description is choice d). HI is the conjugate acid of iodide, I^-. Iodide is the conjugate base of HI.