higher chemistry - alcohols and carboxylic acids - units 2.2 + 2.3

unit 2 - nature's chemistry

what is the functional group?

hydroxyl group

link between molecular size and boiling point of alcohols

as molecular size increases, boiling point increases due to increasing london dispersion forces, so more energy is required to break them

link between the number of hydroxyl groups in a molecule and it’s viscosity

as the number of hydroxyl groups in a molecule increases, viscosity increases due to more hydrogen bonds, making the molecules more difficult to move over eachother quickly

link between molecular size and solbulity of alcohols in water

as molecular size increases, solubility decreases as the carbon chain part of the molecule is non polar and insoluble in water

link between moelcular size and boiling point of carboxylic acid

as the molecular size increases, boiling point increases as intermolecular forces increase and a hydrogen bond which require more heat energy to overcome

why is the number of electrons relevant when comparing boiling points of different compounds

molecules with the same amount of electrons will have LDFS but if there are big differences, hydrogen bonding is present

why are smaller carboxylic acids soluble in water

they’re polar and water is a polar solvent, like dissolves like

why are larger carboxlyic acids insoluble in water

as the hydrocarbon chain increases, polarity of the molecule decreases, making it non polar and insoluble in water