Which of the following,upon treatment with $tert-BuONa$ followed by addition of bromine water,fails to decolourize the colour of bromine?

For the given reaction
$R_1-C(R)(X)-R_2 \xrightarrow{HOH} R_1-C(R)(OH)-R_2$
Which substrate will give maximum racemisation?

Which of the following statements is true in the case of alkyl halides?

Which of the following compounds has the fastest $S_N2$ reaction rate?

Find the reactants which on heating with alcoholic $KOH$ produce the compound $CH_3-CH_2-CH_2-CH=CH_2$.
$(i) \ CH_3-CH(Br)-CH_2-CH_2-CH_3$
$(ii) \ CH_3-CH_2-CH(Br)-CH_2-CH_3$
$(iii) \ CH_3-CH_2-CH_2-CH_2-CH_2Br$
$(iv) \ CH_3-CH_2-CH_2-CH(Br)-CH_3$

Predict all the alkenes that would be formed by dehydrohalogenation of the following halides with sodium ethoxide in ethanol and identify the major alkene:
$(i)$ $1-$Bromo$-1-$methylcyclohexane
$(ii)$ $2-$Chloro$-2-$methylbutane
$(iii)$ $2,2,3-$Trimethyl$-3-$bromopentane.