Answer:
d) PO4^3-, HPO4^2-
Explanation:
Basically, an acid and a base which differs only by the presence or absence of proton (hydrogen ion) are called a conjugate acid-base pair.
a) HI, I
This is incorrect. For the acid, HI the conjugate base is I⁻ ion.
b) HCHO2, SO4^2-
This is incorrect, there's no relationship between both entities.
c) CO3^2-, HCI
This is incorrect, there's no relationship between both entities.
d) PO4^3-, HPO4^2-
This is correct. The difference between both entities is the Hydrogen ion. This is the conjugate acid-base pair
