What is the product formed when $1$-bromo-$3$-chlorocyclobutane reacts with $2$ moles of sodium in ether?

Chloroform reacts with concentrated $HNO_{3}$ to give

The reaction of $CH_3-CH=CH-C_6H_4-OH$ with $HBr$ gives:

Which one of the following compounds is inactive towards $S_N1$ reaction?

An alkene $X$ $(C_4H_8)$ on reaction with $HBr$ gave $Y$ $(C_4H_9Br)$. Reaction of $Y$ with benzene in the presence of anhydrous $AlCl_3$ gave $Z$,which is resistant to oxidation with $KMnO_4-KOH$. What are $X, Y, Z$ respectively?

Among the following,which will readily undergo $S_{N}2$ reaction?