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Question
Give the balanced equations for the reaction with two different amphoteric oxides with a caustic alkali.
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Solution
Zinc oxide:
\[\ce{\underset{white}{ZnO} + \underset{(colourless soluble)}{\underset{caustic soda}{2NaOH}}-> \underset{sodium zincate}{Na2ZnO2} + H2O}\]
Aluminium oxide:
\[\ce{\underset{white}{Al2O3} + \underset{caustic soda}{2NaOH}->\underset{(white)}{\underset{sodium meta aluminate}{2NaAlO2}} + H2O}\]
RELATED QUESTIONS
State your observations when Barium chloride solution is mixed with Sodium Sulphate 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 |
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 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 a 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 excess of ammonium hydroxide is added to it?
(v) Which solution gives a white precipitate with excess ammonium hydroxide?
State the colour of the residue formed when nitrates of :
1. Calcium
2. Zinc
3. Lead
4. Copper are strongly heat
When an ammonium hydroxide solution is added to solution B, a pale blue precipitate is formed. This pale blue precipitate dissolves in excess ammonium hydroxide giving an inky blue solution. What is the cation present in solution B?
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 balanced equation for a metal that evolves a gas which burns with a pop sound when boiled with alkali solutions.
