Question

Potassium chromate solution is added to aqueous solutions of metal nitrate. The yellow precipitate thus obtained are insoluble in acetic acid. These are subjected to flame test, flame colour of individual ppt. is/are:

• A. Lilac
• B. Apple green
• C. Crimson red
• D. Blue

Answer 1

Answer: (B)

Apple green

Answer 2

When potassium chromate, $\text{K}_2\text{CrO}_4$, is added to an aqueous solution of a metal nitrate that contains $\text{Ba}^{2+}$ ions, a yellow precipitate of barium chromate, $\text{BaCrO}_4$, is formed. This precipitate is insoluble in acetic acid. In the flame test, $\text{Ba}^{2+}$ ions impart an apple green color.