Chapter 15 - Haloalkanes Flashcards
Haloalkanes
- contain carbon, hydrogen and at least one halogen
how to name haloalkanes and prefixes
- order alphabetically (excl. di, tri, tetra etc…)
- fluoro
- chloro
- bromo
- iodo
primary, secondary, tertiary haloalkanes
primary - C attached to 2 H and one alkyl group
secondary - C attached to 1 H and two alkyl group
tertiary - C attached to no H and three alkyl group
Carbon - Halogen bond
- as halogens are more electronegative then carbon, carbon will be slightly positively charged and halogen will be slightly negatively charged
- bond is polar
- can act as nucleophiles
nucleophiles
- atom or grp/of atoms which are attracted to an electron deficient centre/atom where it donates a pair of electrons to form a covalent bond
- electron pair donor
nucleophile example
OH-
Br-
H2O
NH3
reaction mechanism
nucleophilic substitution
nucleophilic substitution
- when haloalkane reacts with nucleophile, nucleophile replaces halogen in substitution reaction
- undergone by primary haloalkanes with range of nucleophiles to produce a variety of compounds
Hydrolysis
- chemical reaction involving water or aqueous solution of hydroxide that causes the breaking of a bond in a molecule
- results in molecule being split into two products
nucleophilic substitution reactants, products and conditions
- haloalkane and nucleophile
- alcohol and halide ion
- NaOH & heat under reflux
what else do haloalkanes react with
water - slower reaction then with hydroxide ions
H3CX + H2 –> H3COH + HX
reactivity of haloalkanes
- as you go down the group the haloalkanes become more reactive
- due to bond enthalpy decreasing as atoms are less electronegative going down the group so bonds are weaker
how to test reactivity of haloalkanes
add AgNO3 and record the rate of which the precipitate forms
Organohalogens
compounds that have at least one halogen atom joined to a carbon chain
what are organohalogens used as
refrigerants, flame retardants, solvents and to make polymers
