Which is the main organic product obtained by the reaction of $2,2,2-$trichloroethanol with calcium hydroxide?

$S_{N}1$ and $S_{N}2$ products are the same (excluding stereoisomers) for which of the following compounds?

When $3-$methylbutan$-2-$ol is treated with $HBr$,the following reaction takes place:
$CH_3-CH(CH_3)-CH(OH)-CH_3 \xrightarrow{HBr} CH_3-C(Br)(CH_3)-CH_2-CH_3$
Give a mechanism for this reaction.
(Hint : The secondary carbocation formed in step $II$ rearranges to a more stable tertiary carbocation by a hydride ion shift from $3^{rd}$ carbon atom.)

Predict the product for the following reaction:
$\xrightarrow[\Delta]{alc. \ KOH}$ product

The reaction of $1$-chlorobutane with alcoholic $KOH$ yields .....

Ethyl bromide reacts with lead-sodium alloy to form