Question

Which compound in solution produces a precipitate with aqueous ammonia that does not dissolve when an excess of ammonia is added?Q3 1 cm3 of solution Q was added into two separate test tubes. To one of the test tubes, an excess of aqueous sodium hydroxide was added gradually. White precipitate which was soluble in excess aqueous sodium hydroxide was obtained. To the other test tube, an excess of aqueous ammonia was added gradually. White precipitate which was insoluble in excess aqueous ammonia was obtained. What could solution Q contain?
1 point
A lead(II) chloride
B aluminium chloride
C calcium chloride
D ammonium chloride​

Answer 1

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Answer 2

1 Answer

A milky white precipitate was formed when solution containing aluminum cations is treated with ammonium hydroxide. The white precipitate does not dissolve on adding excess ammonia solution. No further reaction is seen on heating. A WHITE ppt was formed on treating cadmium cations with ammonium hydroxide which does not dissolve immediately on adding xs ammonia. No reaction is seen on heating, apart from the formation of a few white ppt. Cadmium Hydroxide was precipitated which formed a complex soluble ion on adding xs ammonia.