Identify the incorrect statements regarding primary standard of titrimetric analysis. (A) It should be purely available in dry form. (B) It should not undergo chemical change in air. (C) It should be hygroscopic and should react with another chemical instantaneously and stoichiometrically. (D) It should be readily soluble in water. (E) $$KMnO_4$$ & $$NaOH$$ can be used as primary standard. Choose the correct answer from the options given below :

Identifying incorrect statements about primary standards:

(A) "It should be purely available in dry form" — Correct property of a primary standard.

(B) "It should not undergo chemical change in air" — Correct property.

(C) "It should be hygroscopic and should react with another chemical instantaneously and stoichiometrically" — Incorrect. A primary standard should be NON-hygroscopic (not absorb moisture from air).

(D) "It should be readily soluble in water" — Correct property.

(E) "$$KMnO_4$$ and NaOH can be used as primary standard" — Incorrect. Neither $$KMnO_4$$ nor NaOH are primary standards. $$KMnO_4$$ is not pure enough, and NaOH is hygroscopic and absorbs CO₂.

The incorrect statements are (C) and (E).

The correct answer is Option 2: (C) and (E) only.