halogenoalkanes (organic)

Question 1

are halogenoalkanes soluble in water?

Answer 1

C-H bonds are non-polar so they are insoluble

Question 2

do halogenoalkanes have a polar bond? why?

Answer 2

yes they are polar because halogens have a higher electronegativity than carbon

Question 3

intermolecular forces in halogenoalkanes? why?

Answer 3

permanent dipole-dipole and van der Waals forces of attraction because C-X bond polarity creates permanent dipoles

Question 4

When do halogenoalkanes boiling points increase

Answer 4

carbon chain length increases, halogen is further down group 7

Question 5

what is the most important factor in determining their reactivity

Answer 5

carbon-halogen bond enthalpy

Question 6

what is the order of reactivity of halogenoalkanes

Answer 6

bond enthalpy of C-X decreases down the group, so reactivity increases down the group

Question 7

what is a nucleophile

Answer 7

a negatively charged ion/ atom with a lone pair of electrons which can be donated to an electron deficient atom

Question 8

3 examples of nucleophiles

Answer 8

:OH-
:CN-
:NH3

Question 9

what is nucleophilic substitution

Answer 9

a reaction where a nucleophile donates a lone pair of electrons to a delta+ C atom. delta- atom leaves molecule

Question 10

what are CFCs

Answer 10

chlorine-fluro-carbons - haloalkanes containing C, F and Cl only (no H)

Question 11

whats the problem with CFCs

Answer 11

although reactive under normal conditions, they catalyse the breakdown of ozone in the atmosphere via free radical substitution

Question 12

What are CFCs being replaced with?

Answer 12

HCFCs (hydrogen, chlorine, fluorine, carbon)
HFCS (hydrogen, fluorine, carbon)

Question 13

conditions/reactants needed for the elimination reaction of halogenoalkanes

Answer 13

NaOH or KOH dissolved in ethanol (no water)
heated

Question 14

what is formed in an elimination reaction of haloalkanes

Answer 14

alkene, water and halogen ion