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Question
What do you understand by the following:
Qualitative analysis
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Solution
The analysis which involves the identification of the unknown substances in a given sample is called qualitative analysis.
RELATED QUESTIONS
Name a white, insoluble oxide that dissolves when fused with caustic soda or caustic potash.
What do you understand by the following:
Reagent
What do you understand by the following:
Precipitation
Z is a compound. With dilute HCl it gives a gas turning dichromatic solution green. Z gives lilac flame. Name Z.
State what do you observe when:
Sulphur burns.
State what do you observe when:
Ethane is bubbled through a solution of bromine in tetrachloromethane (carbon tetra chloride).
Match the following :
| Column A | Column B |
| 1. A substance that turns moist starch iodide paper blue. |
A. Ammonium sulphate |
| 2. A compound which releases a reddish brown gas on reaction with concentrated sulphuric acid and copper turnings. |
B. Lead carbonate |
| 3 . A solu tion of this compound gives a dirty green preci pi ta te with sodium hydroxide. |
C. Chlorine |
| 4 . A compound which on heating with sodium hydroxide produces a gas which forms dense white fumes with hydrogen chloride. |
D. Copper nitrate |
| 5 . A white solid which gives a yellow residue on heating. |
E. Ferrous sulphate |
Identify the substance P based on the information given below:
The deliquescent salt P, turns yellow on dissolving in water, and gives a reddish brown precipitate with sodium hydroxide solution.
Sodium hydroxide solution is added first in a small quantity, then in excess to the aqueous salt solution of copper (II) sulphate, zinc nitrate, lead nitrate, calcium chloride and iron (III) sulphate. Copy of the following table and write the colour of the precipitate in (i) to (v) and the nature of the precipitate (soluble or insoluble) in (vi) to (x).
|
Aqueous salt solution |
Colour of the precipitate when NaOH is added in small quantity |
Nature of the(soluble or insoluble) when NaOH is added in excess |
|
copper (II) sulphate zinc nitrate lead nitrate calcium chloride Iron (III) sulphate |
(i) (ii) (iii) (iv) (v) |
(vi) (vii) (viii) (ix) (x) |
Write balanced equation for a coloured metallic oxide which dissolves in alkalis to yield colourless solutions.
