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Question
When an ammonium salt is warmed with sodium hydroxide solution, a gas is evolved. State three ways in which you could identify this gas.
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Solution
\[\ce{NH4Cl + NaOH -> NaCl + H2O + NH3}\]
The gas that evolved is ammonia.
Tests for Ammonia gas:
- It has a sharp, characteristic odour.
- It gives dense white fumes with conc. HCl.
\[\ce{NH3 + HCl -> NH4Cl}\] - It gives light to deep Brown Colour or ppt. with nessler’s solution K2HgI4.
RELATED QUESTIONS
Identify the salts P and Q from the observations given below:
On performing the flame test salt P produces a lilac coloured flame and its solution gives a white precipitate with silver nitrate solution, which is soluble in Ammonium hydroxide solution.
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Sodium hydroxide solution is added first in a small quantity, then in excess to the aqueous salt solutions of copper (II) sulphate, zinc nitrate, lead nitrate, calcium chloride and iron (III) sulphate. Copy the following table and write the colour of the precipitate in (i) to (v) and the nature of the precipiatate (soluble or insoluble) in (vi) to (x)
| Aqueous salt Solution | Colour of Participitate when NaOH is added in a samll quantity | Nature of precipitate(soluble or insoluble) when NaOH added in excess |
| Copper (II) Solution | ||
| Zinc nitrate | ||
| Lead nitrate | ||
| Calcium chloride | ||
| Iron(III) sulphate |
Write balanced equation for a coloured metallic oxide which dissolves in alkalis to yield colourless solutions.
The questions (i) to (v) refer to the following salt solutions listed A to F.
A.Copper Nitrate
B.Iron (II) Sulphate
C.Iron (III) chloride
D.Lead Nitrate
E.Magnesium sulphate
F.Zinc chloride
(I)Which two solutions will give a white precipitate when treated with dilute hydrochloric acid followed by a barium chloride solution?
(II)Which two solutions will give a white precipitate when treated with dilute nitric acid followed by silver nitrate solution?
(III)Which solution will give white precipitate, when either dilute hydrochloric acid or dilute sulphuric acid is added to it?
(IV)Which solution becomes a deep/inky blue colour when the excess of ammonium hydroxide is added to it?
(V)Which solution gives a white precipitate with an excess of ammonium hydroxide solution?
Write a balanced equation of a coloured metallic oxide which dissolves in alkalis to yield colourless solutions.
Write balanced equation for a metal that evolves a gas which burns with a pop sound when boiled with alkali solutions.
Write a balanced equation for a coloured metallic oxide which dissolves in alkalis to yield colourless solutions.
Write balanced equation for a coloured metallic oxide which dissolves in alkalis to yield colourless solutions.
