Question

In which of the following set/s, reactant and reagent are correctly matched to get ethyl isonitrile as major product?

• A. I, III
• B. II, III
• C. I only
• D. II only

Hint:

AgCN = Isonitrile; KCN = Nitrile (Cyanide).

Answer 1

The Correct Option is C

Step 1: Understand the goal.
We want to make ethyl isonitrile as the main product. We must match the reactant and reagent that give the isonitrile, not the normal nitrile.

Step 2: Recall the key reagent rule.
When an alkyl halide reacts with silver cyanide $AgCN$, the main product is the isonitrile. With potassium cyanide $KCN$, the main product is the normal nitrile.

Step 3: Explain why.
In $AgCN$ the silver-carbon-nitrogen bond is covalent, so the nitrogen lone pair attacks and we get the isonitrile, $R-NC$. In $KCN$ the bond is ionic and the carbon attacks, giving the nitrile, $R-CN$.

Step 4: Pick the right reactant.
To make ethyl isonitrile we use ethyl chloride reacting with $AgCN$. This combination favours the isonitrile.

Step 5: Check the sets.
Among the given sets, only set I correctly pairs the ethyl halide with $AgCN$ to give the isonitrile as the major product.

Step 6: State the answer.
So set I only is the correct match. \[ \boxed{\text{I only}} \]