Assertion (A) : `(CH_(3))_(3)C-O-CH_(3)` gives `(CH_(3))_(3)C-I` and `CH_(3)OH` on treatment with HI.
Reason (R ) : The reaction occurs by `S_(N)1` mechanism.

Options

A. Both A and R are true and R is the correct explanation of A
B. Both A and R are true but R is NOT the corrrect explanation of A
C. A is true but R is false
D. A is false and R is True

Explanation

To analyze the given assertion and reason, we will break down the reaction and the mechanism involved step by step.

### Step 1: Understand the Reaction
The compound `(CH₃)₃C-O-CH₃` is known as tert-butyl methyl ether. When treated with hydroiodic acid (HI), it undergoes a reaction to yield `(CH₃)₃C-I` (tert-butyl iodide) and `CH₃OH` (methanol).

### Step 2: Mechanism of the Reaction
The reaction proceeds via the `S_N1` mechanism. In this mechanism, the reaction involves two main steps:

1. **Protonation of the Ether Oxygen**: The ether oxygen is protonated by the acid (HI), which makes it a better leaving group. This step leads to the formation of a carbocation.

2. **Formation of Products**: Once the ether oxygen is protonated, the bond between the carbon and the oxygen breaks, leading to the formation of a tert-butyl carbocation `(CH₃)₃C⁺`. Iodide ion (I⁻) from HI then attacks this carbocation to form `(CH₃)₃C-I`. Meanwhile, the other part of the ether, which is `CH₃OH`, is also formed.

### Step 3: Conclusion
Thus, the assertion is correct as the reaction does yield `(CH₃)₃C-I` and `CH₃OH` upon treatment with HI. The reason is also correct as the reaction occurs via the `S_N1` mechanism.

### Final Answer
Both the assertion (A) and the reason (R) are true, and the reason correctly explains the assertion.

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