Answer any FOUR of the following questions.
b. How do you prepare methoxy ethane by Williamson's ether synthesis?

Explanation

(a) Step 1 : Formation of proptonated alcohol.

Step 2 : Formation of carboncation :
`H-underset(H)underset(|)overset(H)overset(|)(C )-underset(H)underset(|)overset(H)overset(|)(C )-overset(H)overset(|)(underset(ddot)O)-Hoverset("Slow")( Step 3: Elimination of proton -

(b) When sodium sodium ethoxide is heated with methyl iodide (in alcoholic medium), methoxyethane is formed
`underset("Sodium ethoxide")(CH_3CH_2)-ONa) + underset("Methoxy iodine")(I-CH_3) underset(Delta)overset("Alcohol")(rarr)underset("Methoxy methane")(CH_3CH_2-O-CH_3+NaI)`
Detailed Answer:
(b) In a Williamson synthesis, an ether is formed by reacting an alcohol and an alkyl halide in the presence of a base.
When `CH_3-I` is mixed with the base, like `NaOH`, the alcohol is deprotonated, leaving a negatively charged oxygen. This acts as a nucleophile and attacks the carbon bonded to the halogen(iodide). The halogen, a good leaving group, is released, leaving behind methoxy ethane.