Chemistry
Which of the following is the best reagent to distinguish lead nitrate and zinc nitrate ?
P NaOH solution
Q KOH solution
R NH4OH solution
Only P
Only R
Only Q
Both P and Q
Answer
Only R
Reason
- With NaOH (P) or KOH (Q), both lead nitrate and zinc nitrate give a white precipitate that dissolves in excess alkali, so they cannot be distinguished.
- With NH₄OH (R):
- Lead nitrate gives a white precipitate insoluble in excess NH₄OH.
- Zinc nitrate gives a white precipitate soluble in excess NH₄OH (forms a soluble complex).
Hence, NH₄OH solution is the best reagent to distinguish between the two.
Related Questions
A metal which produces hydrogen on reacting with alkali as well as with acid:
- Iron
- Magnesium
- Zinc
- Copper
The salt solution which does not react with ammonium hydroxide is:
- Calcium nitrate
- Zinc nitrate
- Lead nitrate
- Copper nitrate
Assertion (A): Calcium salt solution does not show any change even after adding an excess of ammonia solution to it.
Reason (R): The low concentration of hydroxide ion in ammonium hydroxide solution which are unable to precipitate the hydroxide ions of calcium
- Both A and R are true and R is the correct explanation of A.
- Both A and R are true but R is not the correct explanation of A.
- A is true but R is false.
- A is false but R is true.
Assertion (A): Iron (II) salt solution when reacted with ammonium hydroxide forms a dirty green precipitate.
Reason (R): Iron salts are brown in colour.
- Both A and R are true and R is the correct explanation of A.
- Both A and R are true but R is not the correct explanation of A.
- A is true but R is false.
- A is false but R is true.