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For a polybasic acid, the dissociation c...

For a polybasic acid, the dissociation constants have a different values for each step e.g.
`H_(3)AhArrH^(+)+H_(2)A^(-),K=K_(a_(1))`
`H_(2)A^(-)hArrH^(+)+HA^(2-),K=K_(a_(2))`
`HA^(2-)hArrH^(+)+A^(3-),K=K_(a^(3))`
What is the observed trend of dissociation constants in successive stages ?

A

`Ka_(1)gtKa_(2)gtKa_(3)`

B

`Ka_(1)=Ka_(2)=Ka_(3)`

C

`Ka_(1)ltKa_(2)ltKa_(3)`

D

`Ka_(1)=Ka_(2)+Ka_(3)`

Text Solution

Verified by Experts

The correct Answer is:
A
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