Which of the following possesses the highest melting point?

Out of $o$- and $p$-dibromobenzene,which one has a higher melting point and why?

$A$ solution of cyclohexene in benzene is stirred at $0 \ ^oC$ while concentrated sulphuric acid is added. After washing away the acid and removing the excess benzene,what product is isolated?

The strongest ortho-para and strongest meta-directing groups respectively are

Describe the reactions of aryl halides with metals.

Assertion : $S_{N}2$ reaction of an optically active aryl halide with an aqueous solution of $KOH$ always gives an alcohol with opposite sign of rotation.
Reason : $S_{N}2$ reactions always proceed with retention of configuration.