MEDIUM
Chemistry
IMPORTANT
Earn 100
To a solution of a substance, gradual addition of ammonium hydroxide results in a brownish black precipitate which does not dissolve in excess of . However, when (not in excess) is added to the original solution, a green precipitate is formed. The solution contained:
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Important Questions on Theoretical Principles of Experimental Chemistry
MEDIUM
Chemistry
IMPORTANT
Black precipitate of copper sulphide dissolves in
MEDIUM
Chemistry
IMPORTANT
The reagents, and aqueous will precipitate:
MEDIUM
Chemistry
IMPORTANT
An aqueous solution of a metal salt reacts with carbon dioxide to give a water soluble compound which on heating gives the starting metal salt back. when present in water does not produce lather with soap. The compounds and , respectively are
EASY
Chemistry
IMPORTANT
When chloride is dissolved in concentrated a blue solution is obtained. Upon dilution with water. The color changes to pink because
MEDIUM
Chemistry
IMPORTANT
Aqueous solution of metallic nitrate reacts with to form , which dissolves in excess . The resulting complex is reduced by acetaldehyde to deposit the metal. and , respectively are:
HARD
Chemistry
IMPORTANT
Which of the following pairs comprises the red precipitates?
HARD
Chemistry
IMPORTANT
A coloured solution of an inorganic salt reacts with potassium thiocyanate to give first a black precipitate, which slowly turns white. The salt solution also gives black precipitate with gas in a slightly acidic medium. The black precipitate dissolves in potassium cyanide forming a colourless solution. The basic radical present in the inorganic salt is:
EASY
Chemistry
IMPORTANT
To avoid the precipitation of hydroxides of along with those of the third group cations, the solutions should be:
