Question

Which of the following statements is/are true? I: The conjugate acid of C6H5NH2 is C6H5NH3+ II: An acid with Ka = 1x10−3 is stronger than an acid with Ka = 1x10−4 III: A strong acid will be completely dissociated at equilibrium A) Only I B) Only II C) I and III D) II and III E) I, II, and III

Answer 1

Answer:

E. I, II, and III.

Explanation:

I. C6H5NH2 + H2O --> C6H5NH3^+ + OH-

C6H5NH2 is a weak base means it is a good proton donor (strong conjugate acid).

II. Any aqueous acid with a pKa value of less than 0 is almost completely deprotonated and is considered a strong acid.

pka1 = - log[1 x 10^-3]

= 2

pka1 = - log[1 x 10^-4]

= 3

pka1 is a stronger acid.

III. A strong acid will be completely dissociated at equilibrium.