Which of the following is an oxyacid?

Which of the following can act as an acid and as a base?

Which is the strongest of the following acids?

The species: $H_{2}O$,$HCO_{3}^{-}$,$HSO_{4}^{-}$,and $NH_{3}$ can act both as Bronsted acids and bases. For each case,give the corresponding conjugate acid and base.

In the following acid-base reactions,in which case can the backward reaction be favoured?

Which of the following substances acts as a base when reacted with water?