Which of the following compounds reacts with $KCN$ to form a cyanide?

Which of the following compounds cannot undergo dehydrohalogenation?

The hydrolysis of $2$-bromo-$3$-methylbutane by the $S_N1$ mechanism primarily yields:

The correct order of $S_N1$ reactivity for the following compounds is:
$(I)$ $CH_3CH_2CH_2CH_2Br$
$(II)$ $CH_2=CH-CH(Br)CH_3$
$(III)$ $CH_3CH_2CH(Br)CH_3$

$ . . . . . . $ compound is slowly oxidized by air in the presence of light to an extremely poisonous gas, carbonyl chloride.

The product $X$ is
[Image: $1-$chloro$-1-$($2$-chloroethyl)cyclopentane] $\xrightarrow{LiBr/DMSO, S_N2 \text{ conditions}}$ Major product $(X)$