Assertion (A) The boiling points of alkyl halides decrease in the order $\mathrm{RI}>\mathrm{RBr}>\mathrm{RCl}>\mathrm{RF}$
Reason (R) The boiling points of alkyl chlorides, bromides and iodides are considerably higher than that of the hydrocarbon of comparable molecular mass.
Assertion (A) KCN reacts with methyl chloride to give methyl isocyanide.
Reason (R) $\mathrm{CN}^{-}$is an ambident nucleophile.
Assertion (A) tert-butyl bromide undergoes Wurtz reaction to give 2,2,3,3-tetramethylbutane.
Reason (R) In Wurtz reaction, alkyl halides react with sodium in dry ether to give hydrocarbon containing double the number of carbon atoms present in the halide.
Assertion (A) Presence of a nitro group at ortho or para position increases the reactivity of haloarenes towards nucleophilic substitution.
Reason (R) Nitro group, being an electron withdrawing group decreases the electron density over the benzene ring.
Assertion (A) In monohaloarenes, further electrophilic substitution occurs at ortho and para positions.
Reason (R) Halogen atom is a ring deactivator.