Ka1 , Ka2 and Ka3 are the respective ionisation constants for the following reactions.
H2S ⇄ H+ + HS–
HS– ⇄ H+ + S2–
H2S ⇄ 2H+ + S2–
The correct relationship between Ka1 , Ka2 and Ka3 is
(i) Ka3 = Ka1 × Ka2
(ii) Ka3 = Ka1 + Ka2
(iii) Ka3 = Ka1 - Ka2
(iv) Ka3 = Ka1 / Ka2
