Alcohols And Haloalkanes

Less volatile Higher mp - form h bonds greater solubility due to the polarity of the molecules (decreases as chain gets longer as less of effect on wider molecule)

• Primary alcohol- OH group attached to carbon attached to 2 H and alkyl group • Secondary alcohol- OH group attached to 1 H bond and 2 alkyl groups • Tertiary alcohols - OH group is attached to C w no hydrogen all alkyl

Acidified dichromate ions If alcohol oxidised these reduced from orange to green Cr2O7 2- => Cr3+

+ [O] => aldehyde heat + distil to prevent further reaction +2[O]=> Carboxylic acid heat strong under reflux

+ [O] => ketone heat under reflux to ensure fully reacted

Don’t undergo oxidation reactions Acidified dichromate remains orange

Heat under reflux with acid catalyst eg conc H2SO4 Product is Alkene Reaction is elimination water is removed

Nucleophilic React w hydrogen halides form haloalkanes Heat under reflux w sodium halide and sulfuric acid HBr is formed react to form haloalkane

Carbon halogen bond is polar Carbon ion has a slight positive charge which attracts nucleophiles Nucleophiles replace halogen - nucleophilic sub

OH- ion replaces halogen Carbon halogen bond is broken by heterolytic fission Alcohol is formed Use NaOH heated under reflux

Lower down the group the weaker the carbon halogen bond the more reactive and easier to break down Rate of hydrolysis increases as the strength of the carbon halogen bond decreases

Tertiary rate is the fastest due to the increased stability of the tertiary carbocation

Molecules that contain at least one halogen atom joined to carbon chain Rarely found in nature as they aren’t broken down naturally - concern

Found at outer edge of stratosphere absorb damaging uv radiation Depletion in this leads to damage to species causing more cancer

UV breaks O2 down into O radicals O2 molecules react with O radical which forms ozone Rate formed= rate broken down

Chlorofluorocarbons very stable due to the strength of carbon halogen bond Stable until reach the stratosphere where they are broken into Cl • which catalyse breakdown of ozone

CFCs are broken down via radiation process is photodisociation Forms CF2Cl• + Cl• Propagation 1. Cl• +O3 -> ClO• +O2 2. ClO• + O-> Cl• + O2 O3+O -> 2O2

Nitrogen oxide radicals form during lightning strikes and aircraft travel NO• +O3 -> NO2• + O2 NO2• + O -> NO• + O2 O3+ O -> 2O2