The dissociation of $H_3PO_4$ takes place in how many steps?

The conjugate acid of $H_2PO_4^-$ is

When one equivalent of an acid is mixed with an excess of a strong base,which of the following acids will show the maximum rise in the temperature of the solution?

The position of equilibrium lies to the right in each of these reactions:
$N_2H_5^+ + NH_3 \rightleftharpoons NH_4^+ + N_2H_4$
$NH_3 + HBr \rightleftharpoons NH_4^+ + Br^{-}$
$N_2H_4 + HBr \rightleftharpoons N_2H_5^+ + Br^{-}$
Based on this information,what is the order of acidic strength?

The $CH_3COO^-$ ion is a.......

The strongest Bronsted base among the following anions is: