An acid $HB$ is strong if its proton exchange reaction with water (dissociation) producing the corresponding base $B$ $HB$ $+$ $H_2O$ $\rightarrow$ $ H_3O^+$ $+$ $B$ is complete
- Note the single arrow reaction $\rightarrow$ - Eventual charges of $HB$ and $B$ are not shown in this general formula
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| $HClO_4$ | perchloric acid |
| $HNO_3$ | nitric acid |
| $H_2SO_4$ | sulfuric acid |
| $HCl$ | chlorhydric acid |
| $HBr$ | bromhydric acid |
| $HI$ | iodhydric acid |
Dissociation reactions of these strong acids: $HClO_4$ $+$ $H_2O$ $\rightarrow$ $ H_3O^+$ $+$ $ClO_4^-$ $HNO_3$ $+$ $H_2O$ $\rightarrow$ $ H_3O^+$ $+$ $NO_3^-$ $H_2SO_4$ $+$ $H_2O$ $\rightarrow$ $ H_3O^+$ $+$ $HSO_4^-$ $HCl$ $+$ $H_2O$ $\rightarrow$ $ H_3O^+$ $+$ $Cl^-$ $HBr$ $+$ $H_2O$ $\rightarrow$ $ H_3O^+$ $+$ $Br^-$ $HI$ $+$ $H_2O$ $\rightarrow $ $H_3O^+$ $+$ $I^-$