Chemistry - Salt Analysis Question with Solution | TestHub
A mixture contains . The following steps are performed:
1. NaOH is added NH₃ gas is evolved.
2. Ba²⁺ is precipitated as BaSO₄ by H₂SO₄.
3. Al³⁺ is precipitated by NH₄OH.
Which of the following statements is correct?
Options:
Answer:
Solution:
Question Explanation: Systematic separation of cations using specific reagents.
Concept:
* Group I–III cation separation
* Ammonium interference with hydroxides
* Selective precipitation
Solution:
1. NH₄⁺ evolves NH₃ with NaOH, so it is removed first.
2. Ba²⁺ is precipitated as BaSO₄, which is removed second.
3. Al³⁺ is precipitated last by NH₄OH. This sequence is correct and ensures complete separation.
Step 1: NH₄⁺ + OH⁻ → NH₃ ↑+ H₂O
Step 2: Ba²⁺ + SO₄²⁻ → BaSO₄↓
Step 3: Al³⁺ + 3OH⁻ → Al(OH)₃↓
Final Answer: All cations are separated completely in this sequence.