In the following multiple choice tests, we often abbreviate $ H_3O^+ $ by $ H^+ $ ( Which is actually false, indeed, $ H^+ $ is always fully hydrated in water!)

Which of the following species is amphoteric ? i) H+ ii) OH- iii) H2O iv) H3O+

a) iii) alone only b) ii) and iii) only c) iii) and iv) only d) ii), iii) and iv) e) all

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a) ist correct , $OH^-$ is not amphoteric, because it has hardly any acidic character ( pKa too high )