A student mistakenly added concentrated (12 M ) HCl to sampleof unknown, instead of adding 6M HCl , as directed
(1) At first, a large amount of light-colored precipitateformed, but some dissolved on further addition of concentrated HCl.Write an equations for the reactions that might have occurred.
(2) The precipitate was separated from the supernatant liquidin (1) and was found to be insoluble in hot water. The precipitate turned grey-black upon addition of 6M NH3. The student concluded that the unknown contained Hg2 2+ ion. The student received a low mark on the experiment, because the unknown actually contained all these group 1 cation. Explain what happened.