JEE MAIN - Chemistry (2004 - No. 3)
The conjugate base of H2PO4- is :
$$PO_4^{3-}$$
$$HPO_4^{2-}$$
H3PO4
P2O5
Vysvetlenie
NOTE : Conjugate acid-base differ by $${H^ + }$$
$$\mathop {{H_2}PO_4^ - }\limits_{Acid} \mathop \to \limits^{ - H} \,\mathop {\,HPO{{_4^ - }^ - }}\limits_{conjugate\,\,base} $$
$$\mathop {{H_2}PO_4^ - }\limits_{Acid} \mathop \to \limits^{ - H} \,\mathop {\,HPO{{_4^ - }^ - }}\limits_{conjugate\,\,base} $$