Analytical Chemistry Question 140
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 colored fumes and droplets of a metal appear on the cooler parts of the test tube. The red solid is
Options:
A) $ HgO $
B) $ Pb_3O_4 $
C) $ {{(NH_4)}_2}Cr_2O_7 $
D) $ HgI_2 $
Show Answer
Answer:
Correct Answer: D
Solution:
[d] $ HgI_2 $ on heating liberates $ I_2 $ with $ Hg $ deposition. Also, it is soluble in excess of KI giving $ K_2HgI_4 $ . $ HgI_2\xrightarrow{\Delta }Hg+I_2 $
$ HgI_2+2KI\xrightarrow{{}}K_2HgI_4 $
BETA
