Arrhenius definitions e Arrhenius acids are substances which when dissolved in water. increase the h+ concentration HCI is an Hcl(g)→Hao+Cao Arrhenius acid O Arrhenius bases are substances which. when dissolved in water increase the oh concentration Naoh is an NaOH→Nata+OH (ag) Arrhenius base.Arrhenius Definitions Arrhenius Definitions Arrhenius acids are substances which, when Arrhenius acids are substances which, when dissolved in water, increase the H dissolved in water, increase the H + concentration. concentration. HCl(g) → H + (aq) + Cl − (aq) Arrhenius bases are substances which, when Arrhenius bases are substances which, when dissolved in water, increase the OH dissolved in water, increase the OH − concentration. concentration. NaOH(s) → Na + (aq) + OH − (aq) HCl is an Arrhenius acid. NaOH is an Arrhenius base