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

Match the reactions in List-$I$ with the features of their products in List-$II$ and choose the correct option.
| List-$I$ | List-$II$ |
| :--- | :--- |
| $(P)$ $(-)-1$-Bromo-$2$-ethylpentane $\xrightarrow{aq. NaOH, S_N2}$ | $(1)$ Inversion of configuration |
| $(Q)$ $(-)-2$-Bromopentane $\xrightarrow{aq. NaOH, S_N2}$ | $(2)$ Retention of configuration |
| $(R)$ $(-)-3$-Bromo-$3$-methylhexane $\xrightarrow{aq. NaOH, S_N1}$ | $(3)$ Mixture of enantiomers |
| $(S)$ $(3S, 5S)-5$-bromo-$3$-methylheptane $\xrightarrow{aq. NaOH, S_N1}$ | $(4)$ Mixture of structural isomers |
| | $(5)$ Mixture of diastereomers |

$C_2H_5Br$ $\xrightarrow{KCN} A$ $\xrightarrow{\text{Hydrolysis}} B$
The compound $A$ in the above reaction is

Among the following organic halides,arrange them in the increasing order of their dehydrohalogenation reactions in the presence of alcoholic $KOH$:
$(A)$ $CH_3-CH_2-Br$
$(B)$ $CH_3-CH_2-CH_2-Br$
$(C)$ $CH_3-CH(Br)-CH_3$
$(D)$ $(CH_3)_3-CBr$

In which of the following is the carbon-halogen bond strongest?

The hydrolysis of optically active $2-$bromobutane with aqueous $NaOH$ results in the formation of: