15: Halogenoalkanes

Question 1

halogenoalkane -> alkene

HX is eliminated

Answer 1

elimination reaction
ethanolic NaOH and heat

Question 2

conditions for elimination of HX from a halogenoalkane

Answer 2

ethanolic NaOH and heat

Question 3

reaction type for halogenoalkane to alkene by ethanolic NaOH and heat

Answer 3

elimination reaction

Question 4

producing halogenoalkanes

Answer 4

1. the free-radical substitution - alkanes - UV light
2. electrophilic addition - alkene - halogen or hydrogen halide - at room temperature
3. free-radical substitution - alcohol - by reaction with HX(g); KCl and concentrated H₂SO₄/concentrated H₃PO₄; PCl₃ and heat; PCl₅; SOCl₂ (thionyl chloride)

Question 5

nucleophilic substitution reactions of halogenoalkanes

Answer 5

(a) the reaction with NaOH(aq) and heat to produce an alcohol
(b) the reaction with KCN in ethanol and heat to produce a nitrile
(c) the reaction with NH₃ in ethanol heated under pressure to produce an amine
(d) the reaction with aqueous silver nitrate in ethanol as a method of identifying the halogen present as
exemplified by bromoethane