Here is a $0.400\;M$ solution of $HN_3$
(hydrazoic acid, $K_a = 1.9\cdot 10^{-5}$)
Equilibrium of hydrolysis:
$HN_3$ $+$ $H_2O$ 
$H_3O^+$ $+$ $N_3^-$
Onto which side will shift the reaction to attain equilibrium?
a) to the left side b) to the right side c) it will not shift, because the equilibrium is already attained
The reaction will shift to b) the right side