BP, solubility, volatility Flashcards
solubility of alcohols in water
alcohol solubility is proportional to (solute-solvent) - (solute-solute) - (solvent-solvent)
- memorise table
reflux in ester production
a procedure in which the reaction flask is continually heated while vapours emerging from it are guided through a condenser tube which cools the gases and condenses them back into the flask
- prevents loss of reagent
- allows reaction to perform at higher temps (increasing ROR)
aldehyde and ketone properties
- both have polar carbonyl groups (C=O)
- dipole-dipole and dispersion forces
- increase chain length = decrease in solubility
amines properties
- has a polar NH2 group
- as carbon chain increases the basicity increases and solubility decreases
- in order of basicity tertiary>secondary>primary
- has hydrogen, dipole dipole and dispersion forces
- in order of BP tertiary<secondary<primary
order of alcohol reactivity
- tertiary
- secondary
- primary
hydrocarbons functional group trend
- only dispersion forces
- low BP
- insoluble in water
carboxylic acid functional group trend
- H-bond and polar therefore high BP
- soluble in water
primary alcohols functional group trend
- H-bond and polar therefore high BP
- H in OH group is donor and 2 lone O pairs
amide properties
- have both NH and C=O groups
- have hydrogen, dipole dipole and dispersion
- as MM increases solubility decreases
- in order of BP primary>secondary>tertiary
important apparatus for esterification
- hotplate
- boiling chips (control the boiling by providing nucleation sites for bubbles to dissipate promote even boiling and prevent bumping
- condenser tube
esters functional group trend
- polar bonds
aldehydes and ketones functional group trend
- polar bonds
- increase symmetry = increase reaction efficiency
- increase chain length = decrease in water solubility
primary amide functional group trend
- increase chain length doesn’t increase BP
- H-bond and polar therefore high BP
- soluble in water and solids at 25C
primary amines functional group trend
- H-bond and polar therefore high BP
- 2 H’s of amines are donors and 1 lone N2 pair
- due to trigonal pyramidal geometry, doesn’t stack well, decrease reaction efficiency
- low BP
- soluble in water
BP trends in alcohol
- as carbon chain increases so intermolecular forces increase so BP increases
- as carbon chain increases BP difference btw alkanes and alcohols decreases (dispersion forces dominate in alcohols)
- alcohols BP»»alkanes BP (always)
dissolving alcohols in water process
2 sections:
1. alkyl (non polar and only interacts using dispersion forces)
2. hydroxyl (polar and only interacts using H-bonding and dipole-diple)
solubility trends of alcohol
- carbon chain increases = stronger dispersion forces = decrease solubility
- order of solubility (accessibility of OH group) = tertiary>secondary>primary
carboxylic acid properties
- have polar carbonyl group (COOH)
- as carbon chain increases the acidity and solubility decreases
- in order of acidity tertiary<secondary<primary
- have hydrogen, dipole dipole and dispersion forces
order of alcohols BPs
- primary
- secondary
- tertiary
biodegradability of all polymers
- increase in polarity of bonds = increase in biodegradability
- increase in CH bonds
- C-Cl, C=O, C-N, C-O are easier to biodegrade
- condensation polymers are easier to biodegrade than addition polymers
chemical structure of all polymers
- increase chain length = increase dispersion forces and rigidity and BP
- increase in crystalline (opposite is amorphous) = increase in intermolecular force strength and density/rigidity and BP
- chain branching = loose packing and amorphous molecules
- chain stiffening from large side chains = increase rigidity
purification of ester
- neutralise the excess acid by adding base Na2CO3
- add water to dissolve water soluble substances (e.g salts, etc.)
- add mixture to separating funnel to separate into a dense organic layer and more dense aqueous layer
- the aqueous at the bottom is removed
- repeat 3&4 multiple times
- use distillation to separate ester from other compounds
