Question

Denaturation of alcohol is done by the help of:

• A. $\mathrm{CuSO_4}$ + Pyridine
• B. \(\mathrm{ZnSO}_4\)
• C. \(\mathrm{H}_2\mathrm{SO}_4\)
• D. \(\mathrm{HCl}\)

Hint:

For alcohol denaturation:

- Involves adding toxic organic compounds (e.g., methanol).

- Inorganic acids/salts are not typical denaturants.

- Verify the context for industrial applications.

Answer 1

The Correct Option is A

Step 1: Understand denaturation
Denaturation makes alcohol unfit for drinking by adding toxic or unpleasant substances while maintaining its industrial usefulness.
Step 2: Standard denaturing agents
The most common denaturing mixture is: \[ \mathrm{CuSO_4} \text{ (Copper sulfate)} + \text{Pyridine} \] This combination:

• Gives a blue color to alcohol
• Makes it extremely bitter
• Is difficult to separate

Step 3: Why other options are incorrect

• $\mathrm{H_2SO_4}$: Too corrosive, destroys alcohol
• $\mathrm{ZnSO_4}$: Not an effective denaturant
• $\mathrm{HCl}$: Reacts with alcohol, forms byproducts

Step 4: Mechanism of action
The $\mathrm{CuSO_4}$+Pyridine combination:

• Forms complex compounds with ethanol
• Creates persistent bad taste
• Maintains solvent properties for industrial use