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Question
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 precipitate (soluble or insoluble) in (vi) to (x).
| Aqueous salt solution | Colour of precipitate when NaOH is added in a small quantity | Nature of precipitate (soluble or insoluble) when NaOH is added in excess |
| Copper (II) sulphate | (i) | (vi) |
| Zinc nitrate | (ii) | (vii) |
| Lead nitrate | (iii) | (viii) |
| Calcium chloride | (iv) | (ix) |
| Iron (III) Sulphate | (v) | (x) |
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Solution
| Aqueous salt solution | Colour of precipitate when NaOH is added in a small quantity | Nature of precipitate (soluble or insoluble) when NaOH is added in excess |
| Copper (II) sulphate | (i) Blue | (vi) Insoluble |
| Zinc nitrate | (ii) White gelatinous | (vii) Soluble |
| Lead nitrate | (iii) White chalky | (viii) Soluble |
| Calcium chloride | (iv) White curdy ppt. | (ix) Insoluble |
| Iron (III) Sulphate | (v) Reddish brown | (x) Insoluble |
RELATED QUESTIONS
What do you observe when caustic soda solution is added to the following solution, first a little and then in excess:
ZnSO4
Write a balanced equation for this reaction.
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Sodium hydroxide solution is added to solution A. A white precipitate is formed which is soluble in excess sodium hydroxide. Name the metal ion present in A.
Three test tubes contain calcium nitrate solution, zinc nitrate solution and lead nitrate solution.Describe the effect of Adding sodium hydroxide solution to each portion in turn till it is in excess.
Sodium hydroxide solution is added to the solutions containing the ions mentioned in List X. List Y gives the details of the precipitate. Match the ions with their coloured precipitates.
| List X | List Y |
| (i) Pb2+ | (A) Reddish Brown |
| (ii) Fe2+ | (B) White insoluble inexcess |
| (iii) Zn2+ | (C) Dirty green |
| (iv) Fe3+ | (D) White soluble in excess |
| (v) Cu2+ | (E) White soluble in excess |
| (vi) Ca2+ | (F) Blue |
What is observed when hot, concentrated caustic soda solution is added to zinc? Write a balanced equation.
What is observed when hot, concentrated caustic soda solution is added to aluminium? Write a balanced equation.
State one relevant observation for the following:
To the copper nitrate solution, initially, few drops of sodium hydroxide solution is added and then added in excess.
Name the metal hydroxides which are insoluble in caustic soda solution.
Write the word equation when ammonium salt is heated with caustic soda solution.
