## Chemistry (4th Edition)

(a) Image below: (b) -$H_2C_2O_4$ and $H_3O^+$: Only like acids. - $C_2{O_4}^{2-}$: Only like a base. - $HC_2{O_4}^-$: Both acid and base.
(a) - All you need to do is: Take the structure that is on the question, and remove the hydrogens, until you got the formula you want. (b) - Acids are capable of donating a ($H^+$), and bases can receive one ($H^+$). - $H_2C_2O_4$ and $H_3O^+$, can't receive one proton, but are capable of giving. - $C_2{O_4}^{2-}$, doesn't have one proton, but can receive it. - $HC_2{O_4}^-$: Can both receive and donate.