Question

Identify one cationic radical in the given inorganic salt ``M$_3$'' by performing dry and wet tests.

Hint:

Perform the dry test first to narrow down possibilities, then use targeted wet tests to confirm. For example, a blue precipitate with NH\(_4\)OH confirms Cu\(^2+\), while a white precipitate with BaCl$_2$ confirms Pb\(^2+\).

Answer 1

Aim.
To identify one cation (metal ion) from the given salt "M3" using dry and wet tests.

Apparatus.
Bunsen burner, test tubes, glass rod, droppers, conc. HCl, BaCl2, sodium tetraphenylborate, ammonium hydroxide, etc.

Dry Tests:
Step 1: Flame Test.
Take a small quantity of "M3" and place it in the Bunsen flame. The flame color will help identify the cation.
- Sodium (Na+) will give a yellow flame.
- Potassium (K+) will give a lilac flame.
- Copper (Cu2+) will give a green flame.

Step 2: Action with Concentrated Acids.
Place a small quantity of salt in a test tube and add dilute HCl or HNO3.
Observe any reactions that occur, such as precipitation or gas formation.

Wet Tests:
Step 1: Precipitation with BaCl2.
To a portion of the aqueous extract of "M3", add dilute HCl and BaCl2. Observe for a white precipitate. This indicates the presence of Pb2+ or Ca2+.

Step 2: Reaction with Ammonium Hydroxide.
Add ammonium hydroxide to the solution. If a blue precipitate forms, this suggests the presence of Cu2+.

Step 3: Specific Ion Tests.
- For NH4+ (Ammonium): Add sodium tetraphenylborate to detect NH4+.
- For Fe2+ (Iron): Confirm with potassium ferrocyanide.

Conclusion:
Based on the dry and wet test results, the cationic radical present in "M3" is identified as __________________. (Write the confirmed cation here).