Answer:
H2PO4- is a proton donor and HPO42_ is a proton acceptor
Explanation:
Step 1: What are hydrogen ion donor and acceptor
in the following reaction we see that:
⇒ H2PO4- is more likely to give a H+ ion to form HPO42-.
⇒HPO42- is more likely to take a H+ ion, to form H2PO4-
The reaction of an acid in water solvent is described as a dissociation :
HA ⇔ H+ + A-
⇒where HA is a proton acid
So, H2PO4- = HA and HPO42- = A-
Acids are proton donors. So, H2PO4- is a proton donor and HPO42_ is a proton acceptor