# What type of ions do acids (mostly) contain?

Acids are characterized by the presence of ${H}^{+}$ ions in the solution.
According to Arrhenius concept of acids and bases acids ionize in water to give ${H}^{+}$ ions in solution. Example:
$H N {O}_{3}$ $r i g h t \le f t h a r p \infty n s$ ${H}^{+}$ + $N {O}_{3}^{-}$
${H}_{2} S {O}_{4}$ $r i g h t \le f t h a r p \infty n s$ $2 {H}^{+}$ + $S {O}_{4}^{-} 2$
$H I$ $r i g h t \le f t h a r p \infty n s$ ${H}^{+}$ +${I}^{-}$
You can see that all of the above are acids which ionize in solution to give ${H}^{+}$ ions .