haloalkanes

Question 1

what is the general formula of haloalkanes

Answer 1

CnH2n+2X (X is a halogen)

Question 2

what are the ways haloalkanes can be synthesised

Answer 2

synthesised from alkanes by reaction with halogens in free radical substitutions
in electrophilic addition reactions with alkenes by reaction with. hydrogen halide and to form dihaloalkenes with halogens
by reacting alcohols with halide ions

Question 3

what is the equation for synthesis of chloroalkane(alcohol)

Answer 3

alcohol + HCl —> haloalkane + water

Question 4

what is the equation for synthesis of a bromoalkane (alcohol)

Answer 4

alcohol + NaBr –> bromoalkane + NaOH
(in the presence of conc. sulphuric acid)

Question 5

what is the equation for synthesis of an iodoalkane

Answer 5

alcohol + NaI –> iodoalkane + NaOH
(In the presence of sodium iodide and phosphoric acid)

Question 6

what is a mechanism

Answer 6

pictorial representation of the movement of a pair of electrons during a chemical reaction

Question 7

what does the curly arrow show

Answer 7

the movement of a pair of electrons in a mechanism

Question 8

draw the general mechanism for nucleophilic substitution

Answer 8

Question 9

things to remember for nucleophilic substitution.

Answer 9

the lone pair on the covalent bond forms a covalent bond with the slightly positive carbon atom (shown with curly arrow)
the two electrons in the C-X bond (heterolytic fission)
by gaining the electrons from the bond the halogen atom forms a halide ion.

Question 10

what is a nucleophile

Answer 10

a lone pair donor