Question

Sort the acids according to their strengths in the decreasing order.

• A. $HCl{O}_4$
• B. $HCl{O}_3$
• C. $HCl{O}_2$
• D. $HClO$

Answer 1

More the % oxygen content, more the acidic nature. In general, the overall relative acid strength is:

$N{H}_3$< $C{H}_{3}OH$<Water<${HC{O}_3}^{-}$ < HCN < ${N{H}_4}^{+}$< $H_2$S < $H_{2}C{O}_3$<$C{H}_{3}COOH$ < HF < $HN{O}_2$< $H_{3}P{O}_4$< $H_{2}S{O}_3$< ${HS{O}_4}^{-}$<Hydronium ion< $HN{O}_3$<HCl<HBr< HI < $H_{2}S{O}_4$< $HCl{O}_4$

Those acids which are stronger than H₃O⁺ are completely ionized in aqueous solution. Likewise, the bases which are stronger than OH^- are completely dissociated in aqueous solution. This is known as the levelling effect. The strongest acid and base which can exist in water are H₃O⁺ and OH^-, respectively. This leveling effect is not specific to water (solvent) alone. For example, the strongest acid and base in NH₃ are NH₄⁺ and NH₂^- ions, respectively.