$C_4H_9Cl$ (Optically Active Compound $A$) $\xrightarrow[DMSO]{NaCN}$ $(R)-2-$methylbutanenitrile; Identify compound $A$?

Which of the following alkyl halides is most reactive towards the $E_2$ mechanism?

Sodium tertiary butoxide on reaction with methyl bromide produces the product $P$.
Sodium methoxide upon reaction with tertiary butyl bromide generates the product $Q$.
The products $P$ and $Q$ are

What are $X$ and $Y$ respectively in the following reactions?

Which among the following halide$(s)$ will not show $S_{N}1$ reaction:
$(A)$ $H_2C=CH-CH_2Cl$
$(B)$ $CH_3-CH=CHCl$
$(C)$ $C_6H_5CH_2Cl$
$(D)$ $(CH_3)_2CHCl$
Choose the $most\ appropriate$ answer from the options given below:

$A$ student was carrying out a Grignard reaction between $PhMgBr$ and ethyl benzoate. She ran out of anhydrous ether just after the Grignard reagent was made. Which of the following solvents can still be used to dissolve the ethyl benzoate for its reaction with already formed $PhMgBr$?