In the given reaction:
$CH_3-CH_2-\ddot{S}-CH_2^*-CH_2-Br \xrightarrow{HOH} [X]$
$[X]$ will be:

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

Gem dihalide on hydrolysis gives:

Consider the following reaction,
$C_2H_5Cl + AgCN \xrightarrow{EtOH / H_2O} \underline{X} \text{ (major)}$
Which one of the following statements is true for $\underline{X}$?
$(I)$ It gives propionic acid on hydrolysis
$(II)$ It has an ester functional group
$(III)$ It has a nitrogen linked to ethyl carbon
$(IV)$ It has a cyanide group

Which of the following,on heating with aqueous $KOH$,produces acetaldehyde?

Which compound has the highest reactivity towards $S_{N}1$ reaction?