18. Calculate the concentration of chromate ion, CrO4 2–, in a saturated solution of CaCrO4 (Ksp = 7.1 × 10–4). (A) 2.7 × 10–2 M (B) 3.5 × 10–2 M (C) 7.1 × 10–4 M (D) 3.5 × 10–4 M (E) 5.0 × 10–7 M

20. For a titration reaction of a weak acid, which is correct? (A) The pH of the equivalence point is dependent of the original concentrations or volumes. (B) At the equivalence point, the pH can be found by the pKa of the acid and pKb of the base. (C) The pH of the end point is depended on the pKa of the acid and pKb of the base. (D) The initial pH is not affected by the concentration. (E) The end point is always at the center of the steepest section of the titration curve no matter of the stoichiometry of reactions or the choice of indicator.

18. Calculate the concentration of chromate ion, CrO4
2–, in a saturated solution of CaCrO4 (Ksp
= 7.1 × 10–4).
(A) 2.7 × 10–2 M
(B) 3.5 × 10–2 M
(C) 7.1 × 10–4 M
(D) 3.5 × 10–4 M
(E) 5.0 × 10–7 M

相關試題

相關試卷

18. Calculate the concentration of chromate ion, CrO4 2–, in a saturated solution of CaCrO4 (Ksp = 7.1 × 10–4).(A) 2.7 × 10–2 M(B) 3.5 × 10–2 M(C) 7.1 × 10–4 M(D) 3.5 × 10–4 M(E) 5.0 × 10–7 M

相關試題

相關試卷

18. Calculate the concentration of chromate ion, CrO4
2–, in a saturated solution of CaCrO4 (Ksp
= 7.1 × 10–4).
(A) 2.7 × 10–2 M
(B) 3.5 × 10–2 M
(C) 7.1 × 10–4 M
(D) 3.5 × 10–4 M
(E) 5.0 × 10–7 M