Chloromethane on treatment with excess of ammonia yields mainly

Which of the carbon atoms present in the molecule given below are asymmetric?

Alkyl fluorides are synthesised by heating an alkyl chloride/bromide in presence of _____ or _____.

Which of the compounds will react faster in ${\mathrm{S}}_{\mathrm{N}}1$ reaction with the ${}^{-}\mathrm{OH}$ ion?

${\mathrm{CH}}_3{\mathrm{CH}}_2\mathrm{Cl}$ or ${\mathrm{C}}_6{\mathrm{H}}_5{\mathrm{CH}}_2\mathrm{Cl}$