Question

2. State a chemical test you could perform to distinguish between unlabelled samples of the following

solutions. Give the expected observations.
a) sodium sulfate & calcium nitrate
b) sodium sulfate & sodium nitrate
c) strontium nitrate & strontium hydroxide
d) barium chloride & lithium chloride
3. Compound A gives a lilac flame test colour and produces a white precipitate when added to a solution
of barium chloride. Identify compound A.

Answer 1

2. Chemical tests to distinguish between unlabelled samples of the following solutions and their expected observations are:

a) Sodium sulfate and calcium nitrate: Add dilute hydrochloric acid to the unknown solution. Calcium nitrate will produce a white precipitate while sodium sulfate will not produce any precipitate.

b) Sodium sulfate and sodium nitrate: Add silver nitrate solution to the unknown solution. Sodium nitrate will produce a white precipitate of silver chloride while sodium sulfate will not react.

c) Strontium nitrate and strontium hydroxide: Add dilute hydrochloric acid to the unknown solution. Strontium hydroxide will produce a white precipitate while strontium nitrate will not produce any precipitate.

d) Barium chloride and lithium chloride: Add a few drops of dilute sulfuric acid to the unknown solution, followed by a few drops of a solution of potassium dichromate. Barium chloride will produce a green color while lithium chloride will not show any color.

3. Compound A giving a lilac flame test color and producing a white precipitate when added to a solution of barium chloride indicates the presence of potassium ion (K+). Therefore, compound A is most likely potassium chloride (KCl).