Physical Properties
Physical State
- Phenol - pure phenol is colourless crstalline semi-solid, on reacting with air it form pink colored p-quinone
- Carboxylic Acids - acids upto 10 carbon are liquid at room temp and higher are colourless solid, (all aromatic acids are crystalline solids)
- Carbonyl Compounds - formaldehyde is gaseous at room temp and other carbonyl compounds are liquid at room temp
- Amines - lower amines are gasses and higher are liquids, methyl and ethyl amines have fish-like smell, pure amines are colourless, nitro compounds are yellow
Boiling Point
IMPORTANT
It depends on following factors:
It directly depend on: intermolecular forces(IMF), molecular weight(MW)
It inversely depend on: branching and symmetry(BAS)
- Haloalkanes - IMF: weak vander waal which depends upon size of halogen, MW: number of carbon, nature of halogen
- Haloarenes - IMF: weak vander waal which depends upon size of halogen, MW: nature of halogen
- Alcohols - length of C-chain increase and branching decrease then boiling point increase
- Ethers - IMF: dipole-dipole (polar in nature) b.pt more than alkane, haloalkane but less than alcohol
- Phenol - IMF: strong H-bonding, b.pt more than benzene, haloarene
- Carboxylic Acids - IMF: strong H-bonding(they form dimers), b.pt more than alcohol, aldehyde, ketone, halogen compound, ether etc, basically most of the things
- Carbonyl Compouds - IMF: dipole-dipole(due to polar carbonyl group), ketones have a higher boiling point than aldehyde with same molar mass, b.pt is less than acids, alcohols, amines, but more than halogen compounds, hydrocarbons,
- Amines - IMF: H-bonding, more than halogen compounds, hydrocarbons, ethers, aldehydes, ketones and less than alcohols, carboxylic acids
Melting Point
IMPORTANT
It depends upon packing of molecule in the lattice
- Haloarenes - para > ortho > meta
- Carboxylic Acids - acid with even number of carbon have higher melting point than acid with odd number of carbon of same molar mass, due to better packing
Solubility
IMPORTANT
It depends on polar and non-polar nature of the solute and solvents, we can follow “like dissolve like” rule
- Haloalkanes - they are insoluble in water, soluble in non-polar solvents
- Alcohols - smaller the size, more soluble: lower alcohols(upto 4 carbon) are soluble in water due to H-bonding but higher alcohols are not because bulky alkyl group mask over water in H-bonding
- Ethers - smaller the size, more soluble: lower ether(upto 4 carbon) are soluble in water due to H-bonding but higher ether are not because bulky alkyl group mask over water in H-bonding
- Carboxylic Acids - smaller the size, more soluble: lower acids(upto 5 carbon) are soluble in water due to H-bonding but higher acids are not because bulky alkyyl group mask over water in H-bonding (Benzoing acid is soluble in hot water but not in cold)
- Carbonyl Compounds - smaller the size, more soluble: lower carbonyl compounds(upto 4 carbon) are soluble in water but higher are not because bulky alkyle group mask over water in H-bonding
- Carboxylic Acids - smaller the size, more soluble: lower amines (upto 4 carbon) are soluble in water but higher amines are not because bulky alkyl group mask over water in H-bonding
Stability
- Haloalkanes - size of halogen increase, bond length increase, bond strength decrease, stability decrease
Dipole Moment
IMPORTANT
It depends on the electronegativity,size of atoms and shape of the molecule
for aromatic compounds, less the angle between groups, more will be dipole moment
- Haloalkanes - more EN and bigger size then more dipole moment
- Haloarenes - ortho > meta > para
- Ethers - they have some dipole moment because of polar O-C bonds
Chemical Properties
Acidic Character
IMPORTANT
EDG decrease acidic character, EWG increase it EDG Effect: ortho > para > meta EWG Effect: para > ortho > meta For amines, carboxylic acids, ortho effect always increase acidic character
- Alcohols - no litmus, no effervescence, only hydrogen gas (weakly acidic, weaker than water)
- Phenol - litmus, no effervescence, give hydrogen gas
- Carboxylic Acids - litmus, effervescence, give hydrogen gas
Basic Character
IMPORTANT
EDG increase basic character, EWG decrease it EDG Effect: ortho > para > meta EWG Effect: para > ortho > meta For amines, carboxylic acids, ortho effect always decreases basic character
- Ethers - they have lone pair on oxygen which they donate or gain proton