Which is the set of amphiprotic species?

Options

A. `H_(2)O,H_(2)PO_(3)^(Theta), HPO_(4)^(2-)`
B. `HC_(2)O_(4)^(Theta),H_(2)PO_(4)^(Theta),SO_(4)^(2-)`
C. `H_(2)O,HPO_(4)^(2-),H_(2)PO_(2)^(Theta)`
D. `H_(3)O^(o+),H_(2)PO_(4)^(Theta),HCO_(3)^(Theta)`

Answer

A

Explanation

a. Atmospheric species are those which can loose a proton and can accept a proton.
a. `H_(3)O^(o+)hArr H_(2)O underset(-H^(o+))hArr Ooverset(Theta)H + H^(o+)`
`H_(3)PO_(3) underset(+H^(o+))hArr underset("acid")underset("Dibasic")(H_(2)PO_(3)^(Theta))underset(-H^(o+))hArrHPO_(3)^(2-)+H^(o+)`
`H_(2)PO_(4)^(Theta)underset(+H^(o+))hArrunderset("acid")underset("Tribasic")(HPO_(4)^(2-))underset(-H^(o+))hArrPO_(4)^(3-)+H^(o+)`
b. `H_(2)C_(2)O_(4)overset(+H^(o+))hArrunderset("acid")underset("Dibasic")(HC_(2)O_(4)^(Theta))overset(-H^(o+))hArrC_(2)O_(2)^(2-)+H^(o+)`
`H_(3)PO_(4)overset(+H^(o+))hArrunderset("acid")underset("Tribasic")(H_(2)PO_(4)^(Theta))overset(-H^(o+))hArrHPO_(4)^(2-)+H^(o+)`
`HSO_(4)^(Theta) overset(+H^(o+))hArr underset("acid")underset("Monobasic")(SO_(4)^(2-))rarr "Cannot loose proton"`
c. `H_(3)O^(o+) overset(+H^(o+))hArr H_(2)O overset(-H^(o+))hArr overset(Theta)OH +H^(o+)`
`H_(2)PO_(4)^(Theta) overset(+H^(o+))hArr underset("Tribasic acid")(HPO_(4)^(2-))overset(-H^(o+))hArrPO_(4)^(3-)+H^(o+)`
`H_(3)PO_(2)^(Theta)overset(+H^(o+))hArrunderset("Monobasic acid")(H_(2)PO_(2)^(Theta))rarr "Cannot loss proton"`
d. `"Cannot accept proton" larr H_(3)O^(o+)overset(-H^(o+))hArrH_(2)O+H^(o+)`
`H_(3)PO_(4)overset(+H^(o+))hArrunderset("Tribasic acid")(H_(2)PO_(4)^(Theta))overset(-H^(o+))hArrHPO_(4)^(2-)+H^(o+)`
`H_(2)CO_(3)overset(+H^(o+))hArrunderset("Dibasic acid")(HCO_(3)^(Theta))overset(-H^(o+))hArrCO_(3)^(2-)+H^(o+)`
Hence answer is (a).