A 1.0 x 10^-3 M solution of compound X gives a solution with pH = 10.00. Based on this result X must be a?

Question

A) strong base

B) weak base

C) strong acid

d) weak acid

E) Neutral compound

Please explain the answer so i understand why.

Answer 1

B) weak base

Reasons?

A. This compound X increase pH from 7.0 for water, this it must be a base.

B. If it would be a strong base, it would be completely dissociated to form n x(1.0 x 10^-3 M) OH-, thus pH would be no less than 11.0, where n is an integer.  For example, for base NaOH, n = 1 since one OH- would be formed from one molecule.  For base Mg(OH)2, n = 2.  For base Tl(OH)3, n = 3, etc.