Alcohols and Haloalkanes Flashcards
What kind of intermolecular forces do alcohols have?
hydrogen bonding due to electronegativity difference in the OH bond
Do alcohols have a higher bp and mp compared to other hydrocarbons with similar chain lengths?
HIGHER, DUE TO hydrogen bonding
are alcohols soluble in water? Does solubility depend on chain length?
yes they can form hydrogen bonds. Insoluble when chain is long most of the molecule is non polar C-H bonds which takes precedence
Alcohol + Halide ions (NaBr) = ?
haloalkane and NaOH if its HBr it would be water instead
what is a dehydration reaction?
Reaction where water is lost to form an organic compound.
Alcohol gets dehydrated. What are the reagents conditions and products?
conc sulfuric acid and heated. Products are alkene and water
How is a hydrogen halide made in situ?
a salt is reacted with acid to form the hydrogen halide. E.g. NaBr + H2SO4 = HBr
What do 1) primary, 2) secondary, 3) tertiary alcohols oxidise into?
1) Aldehydes and carboxylic acids
2) Ketones
3) alcohols wont be oxidised
how to form an aldehyde from an alcohol. Also how do you form a carboxylic acid
1) gentle heating primary alcohol with acidified K2Cr2O7 solution and sulfuric acid
2) to get an aldehyde you need a distilling apparatus so the aldehyde (boils at a lower temperature than the alcohol) is distilled off.
Alcohol + (O) = aldehyde + water
To form a Carboxylic acid, alcohol has to be mixed with excess oxidising agent and heated under reflux.
Alcohol + 2(O) =carboxylic acids + water
How to form a ketone from an alcohol
1) Reflux secondary alcohol with acidified K2Cr2O7 and it will produce a ketone
2) Ketones cannot be oxidised easily so even prolonged refluxing wont produce anything more.
What do tertiary alcohols form when oxidised?
Nothing they can’t be oxidised. Only solution is by burning them.
What are haloalkanes?
saturated organic compounds that contain carbon atoms and at least one halogen atoms
Why is the Carbon-halogen bond polar?
as halogens are generally more electronegative than carbon. The delta positive carbon is electron deficient, meaning it can be attacked by nucleophile. So OH-, CN- and NH3 are all nucleophiles which react with haloalkanes. Water is nucleophile too but reacts slowly.
Are haloalkanes soluble in water?
Insoluble due to C-H bonds being non-polar and not compensated for enough by C-X bond polarity.
What type of intermolecular forces do haloalkanes have?
Permanent dipole-dipole and London forces.
Define nucleophile
Electron pair donator
What are three examples of nucleophiles
:OH-
:CN-
:NH3
What is a nucleophiles substitution reaction?
Nucleophile donates lone pair of electrons to delta positive carbon atoms and the delta negative atom leave the molecule and gets replaced.
What is hydrolysis?
A reaction where water is a reactant
What determines how quickly haloalkanes are hydrolysed?
The bond enthalpy, so weaker bond enthalpies mean that they react faster. Iodoalkanes are hydrolysed the fastest and flouroalkanes are hydrolysed the slowest.
What rare CFCs? And their nature?
Chloro-Fluoro-Carbons
Stable, volatile, non-flammable and non-toxic
Write free radical substitution equations to show how cl free radicals catalyse to break down the ozone layer. Also do it for nitrogen.
Check CGP or PMT
