A compound 'X' is acidic and it is soluble in NaOH solution, but insoluble in $NaHC{O}_3$ solution. Compound X also gives violet colour with neutral $FeC{O}_3$ solution. The compound X is

Step-by-Step Reasoning

1. Acidic Nature & Solubility

• Compound X is "acidic" and soluble in NaOH:
  This means X reacts as an acid, forming a salt or getting ionized in strong base.
• X is insoluble in NaHCO₃:
  Carboxylic acids (like benzoic acid or acetic acid) dissolve in both NaOH and NaHCO₃, but weaker acids (like most phenols) do not dissolve in NaHCO₃. So, X is a weak acid—most likely a phenol.

2. Violet Colour with Neutral FeCl₃

• Only phenols (and some enols or salicylates) give characteristic violet, blue or green coloration with neutral FeCl₃, due to complex formation.

3. Conclusion

• Combining these clues:
  • Acidic, but not strong enough to dissolve in NaHCO₃: points to phenol or substituted phenol.
  • Violet colour with FeCl₃: phenol is the textbook example.
• Thus, Compound X is most probably phenol (C₆H₅OH).

Final Answer: Compound X is phenol (C₆H₅OH).