Consider the reactions:
(i) `(CH_(3))_(3)COCH_(3) to CH_(3)I +(CH_(3))_(3) COH`
(ii) `(CH_(3))_(3)COCH_(3) to CH_(3)OH + (CH_(3))_(3) CI`
Which of the following statements is correct? The reagent used in reaction (i) in anhydrous HI in ether and in reaction (ii) is concentrated HI ,. The reagent used in reaction (i) is concentrated HI and in reaction (ii) is anhydrous HI in ether, The reagent used both in reaction (i) and (ii) is concentred HI, The reagent usedboth in reactions (i) and (ii) is anhydrous HI in ether.

Options

A. The reagent used in reaction (i) in anhydrous HI in ether and in reaction (ii) is concentrated HI .
B. The reagent used in reaction (i) is concentrated HI and in reaction (ii) is anhydrous HI in ether
C. The reagent used both in reaction (i) and (ii) is concentred HI
D. The reagent usedboth in reactions (i) and (ii) is anhydrous HI in ether.

Answer

A

Explanation

The low polarity of solvent ether favours the `SN_2` mechanism and high polarity of solvent water favours `S_(N)1` mechanism. The mechanism is `(CH_(3))_(3)COCH_(3) + HI to (CH_(3))_(3) C underset(H)overset(+)OCH_(3) + I^(-)`
`S_(N)1 : (CH_(3))_(3)C overset(+)underset(H)underset(|)OCH_(3) to CH_(3)OH + (CH_(3))_(3) C^(+) overset(r)(CH_(3))_(3)CI`
`S_(N)2: I^(-) + (CH_(3))_(3) C.overset(+)underset(H)underset(|)OCH_(3) to CH_(3)I + HOC (CH_(3))_(3)`