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प्रश्न
How will you distinguish NH4OH solution from NaOH solution?
उत्तर
NH4OH and NaOH can be distinguished by using calcium salts.
For example, when NaOH is added to Ca(NO3)2, Ca(OH)2 is obtained as a white precipitate that is sparingly soluble in excess of NaOH.
\[\ce{Ca(NO3)2 + 2NaOH → Ca(OH)2 + 2NaNO3}\]
When NH4OH is added to calcium salts, no precipitation of Ca(OH)2 occurs, even with an excess of NH4OH. This is because the concentration of OH−ions from the ionization of NH4OH is so low that it cannot precipitate the calcium hydroxide.
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संबंधित प्रश्न
State your observations when ammonium hydroxide solution is added drop by drop and then in excess to each of the following solutions :
1) Copper sulphate solution
2) Zinc sulfate solution.
Name the metal hydroxides which are insoluble in ammonium hydroxide solution.
State two relevant observations of the following:
Ammonium hydroxide solution is added to zinc nitrate solution in minimum quantities and then in excess
Write the observation for the following:
NaOH is added drop-wise till in excess to a solution of zinc sulphate.
Write the observation for the following:
Excess NH4OH is added to a substance obtained by adding hydrochloric acid in silver nitrate solution.
The following table shows the tests a student performed on four different aqueous solutions which are X,Y,Z and W. Based on the observations provided, Identify the cation present
|
Chemical Test |
Observation | Conclusion |
| To Solution X, ammonium hydroxide is added in minium quantity first and then in excess | A dirty white precipitate is formed which dissolves in excess to form a clear solution | (i) |
| To Solution Y, ammonium hydroxide is added in minimum quantity first and then in excess | A pale blue precipitate is formed which dissolves in excess to form a clear inky blue solution | (ii) |
| To solution W, A small quantity of sodium hydroxide solution is added and then in excess | A white precipitate is formed which remains insoluble | (iii) |
| To a salt Z, calcium hydroxide solution is added and then heated | A pungent smelling gas turning moist red litmus paper blue is obtained | (iv) |
Identify the cation of the following case:
NaOH solution when added to solution (A) gives a reddish brown precipitate
Identify the cation of the following case:
NaOH solution when added to solution (C) gives white ppt. which insoluble in excess.
Write balanced equation:
Copper sulphate solution with ammonium hydroxide solution.
Write a balanced equation:
Copper sulphate solution with ammonium hydroxide solution.
