alcohol, phenol, ethers mod4

general formula for alcohol:

R-OH

general formula for phenols

Ar-OH

general formula for ethers:

R1-O-R2

explain an alcohols functional group:

hydroxy (-OH) is bonded to an sp3 hybridised carbon

OH- bearing carbon must have 4 single bonds

how polar Is the OH bond:

oxygen atom is electron rich and hydrogen is poor

COH part of molecule is the polar part and reactive

explain a hydrogen bonds strength:

stronger than dipole-dipole or dispersion forces

explain MP and BP of alcohols

higher MP and BP than hydrocarbons and alkyl halides because they have hydrogen bonds

explain vapour pressure of alcohols

lower vapour pressure than hydrocarbons or alkyl halides of same length

less volatile

hydrogen bonds keep alcohol molecules closer together

explain solubility of alcohols:

high solubility for C1-C3 sized alcohols

solubility decreases as carbon chain gets longer

longer molecules cannot interact with water molecules that want to form h-bonds

common uses of methanol:

lab solvent

denature ethanol for lab use

make formaldehyde

name synthesis of alcohol procedures:

1. fermentation

2. hydration of an alkane

3. nucleophilic of an alkyl halide

explain fermentation:

naturally occurring process

explain hydration of alkane:

H and OH of water molecule is added to the double bond

explain nucleophilic substances of an alkyl halide:

OH ions are attracted to the slight positive charge of the carbon in the C-X bond

what are the 4 key reactions alcohols undergo:

1. reaction with reactive metals

2. dehydration

3. esterification

4. oxidation

explain alcohol reaction with reactive metals:

act as a weak acid in base catalyst:

alcohol + reactive metal → alkoxide salt + water

explain dehydration:

alcohols undergo elimination reaction with catalyst

alcohol → alkene + water

explain esterification:

alcohols react with carboxylic acids to form esters

carboxylic acid + alcohol → ester + water

explain oxidation:

only occurs to primary and secondary alcohols

primary → aldehyde → carboxylic acid

secondary → ketone

explain the structure of ethers:

oxygen joined to 2 carbon groups

explain orbital of ethers:

oxygen is sp³ hybridised and has tetrahedral geometry

explain bonds ethers:

2 polar C-O bonds and no H-bonds because hydrogen is not bonded to an electronegative atom

explain properties of ethers in comparison to alcohols:

lower MP, BP and higher vapour pressure compared to alcohols similar weight because they do not have H-bonds, therefore weaker

explain reactivity of ethers:

almost completely unreactive, used as solvents in organic reactions

explain how to name ethers

use -oxy suffix for shorter carbon side, and add the longer chain

what are phenols

benzene rings with a hydroxy group attached

where are phenols commonly found:

coal tar, petroleum, vanilla

phenol reaction with strong bases:

acidic enough to form conjugate base: phenoxide and water

phenol reactions with weak bases:

not acidic enough to react with weak bases

compare phenols and alcohols acidity:

phenols are more acidic than alcohols without aromatic ring