The base-dissociation constant, Kb for an unknown base is 1.4 10-9. The acid-dissociation constant, Ka, for the conjugate ion is. A) 1.4 × 10-5 B) 10 x 10-7 C)7.1 10-6 D) 7.1 x 10-4 E) 1.4 x 10-23

D) 7.1 x 10-4

Explanation:

Kb = 1.4 x 10^-9

Ka = ?

Relationship between Ka and Kb is given by:

Ka x Kb = Kw

where Kw = ion product constant which relates the concentrations of acids/bases and their conjugates in a solution. The value of this constant is 1.0 × 10^-14

Ka = Kw / Kb

Ka = (1.0 × 10^-14) / (1.4 x 10^-9)

Ka = 0.7142 x 10^-5

Ka = 7.142 x 10^-4

Correct option is D.

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