Advertisements
Advertisements
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.
Advertisements
उत्तर
When NH4OH is added to copper sulphate solution drop-wise, a pale blue ppt. is obtained.
CuSO4 + 2NH4OH 
Cu(OH)2 + (NH4)2SO4 + 4H2O
With the excess of NH4OH, the ppt. dissolves to give a deep blue solution of tetraamine copper(II)sulphate
Cu(OH)2 + (NH4)2SO4 + 2NH4OH [Cu(NH3)4]SO4 + 4H2O
2) When NH4OH is added to zinc sulphate solution drop-wise, a white, gelatinous ppt. is obtained.
ZnSO4 + 2NH4OH Zn(OH)2 + (NH4)2SO4
With the excess of NH4OH, the ppt. dissolves to give a colorless solution of tetraamine zinc(II)sulphate.
Zn(OH)2 + (NH4)2SO4 + 2NH4OH [Zn(NH3)4]SO4 + 4H2O
संबंधित प्रश्न
What happens when ammonia solution is added first dropwise and then in excess to the following solution:
CuSO4
Write a balanced equation for this reaction.
On adding dilute ammonia solution to a colourless solution of a salt, a white gelatinous precipitate appears. This precipitate however dissolves on addition of excess of ammonia solution. Identify (choose from Na, Al, Zn, Pb, Fe)
What is the formula of the white gelatinous precipitate obtained?
Name the metal hydroxides which are insoluble in ammonium hydroxide solution.
Write the observation, and balanced equation for the following reaction:
Ammonium hydroxide is added first in a small quantity, and then in excess, to a solution of copper sulphate.
Distinguish between the following pair of compound using the test given within bracket.
Iron (II) Sulpate an and iron(III) using ammonium hydroxide)
Distinguish between the given pair of compounds using the test given within brackets:
A lead salt and a zinc salt (using excess ammonium hydroxide)
State two relevant observation of the following:
Ammonium hydroxide solution is added to copper (II) nitrate solution in small quantities and then in excess
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) |
Write balanced equation:
Copper sulphate solution with ammonium hydroxide solution.
