Question

Dimethyl glyoxime gives a red precipitate with Ni²⁺, which is used for its detection. To get this precipitate readily the best pH range is

(a) < 1

(b) 2 - 3

(c) 3 - 4

(d) 5 - 9

Answer 1

Correct option  (d) 5 - 9

Explanation:

Nickel (Il) forms a precipitate with the organic compound dimethylglyoxime, C₄H₆(NOH)_2. The formation of the red chelate occurs quantitatively in a solution in which the pH is buffered in the range of 5 to 9.