A red solid is insoluble in water. However, it becomes soluble if some KI is added to water. Heating the red solid in a test tube results in liberation of some violet coloured fumes and droplets of a metal appear on the cooler parts of the test tube. The red solid is

Question

A red solid is insoluble in water. However, it becomes soluble if some KI is added to water. Heating the red solid in a test tube results in liberation of some violet coloured fumes and droplets of a metal appear on the cooler parts of the test tube. The red solid is (A) HgI2 (B) HgO (C) Pb3O4 (D) (N H4)2Cr2O7

Tardigrade Admin · Accepted Answer

HgI2 is orange-red in appearance and hardly soluble in water. It dissolves in excess of I- giving complexes HgI3- and HgI42 - . Violet fumes are liberated due to the release of Iodine gas upon heating.

Q. A red solid is insoluble in water. However, it becomes soluble if some $K I$ is added to water. Heating the red solid in a test tube results in liberation of some violet coloured fumes and droplets of a metal appear on the cooler parts of the test tube. The red solid is

$H g I_{2}$

$H g O$

$P b_{3} O_{4}$

$(N H_{4})_{2} C r_{2} O_{7}$

$H g I_{2}$ is orange-red in appearance and hardly soluble in water. It dissolves in excess of $I^{-}$ giving complexes $H g I_{3}^{-}$ and $H g I_{4}^{2 -}$ . Violet fumes are liberated due to the release of Iodine gas upon heating.

Q. A red solid is insoluble in water. However, it becomes soluble if some KI is added to water. Heating the red solid in a test tube results in liberation of some violet coloured fumes and droplets of a metal appear on the cooler parts of the test tube. The red solid is

HgI2​

HgO

Pb3​O4​

(NH4​)2​Cr2​O7​