`pK_(a)" of "CH_(3)COOH,C Cl_(3)COOH,PhPOHandPhSO_(3)H" are" 4.79,0.9,10.0 and2.6,` Arrange their conjugate bases in increasing leaving tendency.
(b) Which is better leaving group `MeSO_(3)^(-)orCF_(3)SO_(3)^(-)?`
(ii) Why the inversion of configuration is much more during the solvolysis of `C_(6)H_(13)CH(CH_(3))Cl` than `C_(6)H_(5)CH(CH_(3))Cl?`

Explanation

Stronger the acid, weaker will be conjugate base and thus better the leaving group. The acid strength in order decreasing of `pK_(a)` values
`PhOHltCH_(3)COOHltC Cl_(3)COOHltPhSO_(3)H`
Hence leaving tendency of the conjugate base is
`PhO^(-)ltCH_(3)COOH^(-)ltC Cl_(3)COOH^(-)ltPhSO_(3)^(-)`
(b) F shows (-I) effect due to its electron withdrawing nature. Hence, `CF_(3)SO_(3)^(-)` is better leaving group than `MeSO_(3)^(-1)`.
(ii) It depends on the relative stability of the carbocation and subsequent ion-pair carboncation is delocalized on the aromatic ring.
(iii)