Arrange the conjugate bases in decreasing order of basic strength using pKa values of the conjugate acids (ethanol 15.9, phenol 10.0, acetic acid 4.76): $CH X_{3} CH X_{2} O X^{-}$ , $C X_{6} H X_{5} O X^{-}$ , $CH X_{3} COO X^{-}$ .

A $CH X_{3} CH X_{2} O X^{-}$ > $C X_{6} H X_{5} O X^{-}$ > $CH X_{3} COO X^{-}$
B $CH X_{3} COO X^{-}$ > $C X_{6} H X_{5} O X^{-}$ > $CH X_{3} CH X_{2} O X^{-}$
C $C X_{6} H X_{5} O X^{-}$ > $CH X_{3} CH X_{2} O X^{-}$ > $CH X_{3} COO X^{-}$
D $CH X_{3} CH X_{2} O X^{-}$ > $CH X_{3} COO X^{-}$ > $C X_{6} H X_{5} O X^{-}$

Answer: A

The weaker the conjugate acid, the stronger the conjugate base. Order of pKa: ethanol 15.9 > phenol 10.0 > acetic acid 4.76, so basic strength follows ethoxide > phenoxide > acetate.

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Arrange the conjugate bases in decreasing order of basic strength using pKa values of the conjugate acids (ethanol 15.9, phenol 10.0, acetic acid 4.76): CHX3​CHX2​OX−, CX6​HX5​OX−, CHX3​COOX−.

Answer: A

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Arrange the conjugate bases in decreasing order of basic strength using pKa values of the conjugate acids (ethanol 15.9, phenol 10.0, acetic acid 4.76): $CH X_{3} CH X_{2} O X^{-}$ , $C X_{6} H X_{5} O X^{-}$ , $CH X_{3} COO X^{-}$ .