Chem - Organic Chem

what is a hydrocarbon

a compound consisting of only hydrogen and carbon atoms

give me 2 properties of a homologous series

same general formula

similar physical properties

what is crude oil

mixture containing hydrocarbons and impurities

found naturally underground

explain fractional distillation of crude oil

crude oil is heated until most has boiled

passes into fractionating column and rise up, cooler at the top than bottom

fractions with higher boiling points condense lower down while ones with higher b.p. keep rising and condense higher up

hence each fraction is collected and separated

why is cracking done?

larger hydrocarbons are less useful as fuels but have more supply than demand

cracking converts them into smaller hydrocarbons to meet their demand as fuels

and also into alkenes to make polymers

3 ways alkanes change as they get bigger

boiling point increases

viscosity increases

burns less cleanly

substitution reaction of alkanes CONDITIONS

UV light

substitution reaction of alkanes REACTANT

halogen

what is meant by the term saturated

compound containing only C-C single bonds between carbons

what is meant by the term unsaturated

compound containing a C-C double or triple bond

test for alkenes

add bromine water

mixture decolourises from orange

products in any complete combustion reaction

carbon dioxide and water

CONDITION for alkene addition reaction w/ halogen

UV

PRODUCT for alkene addition reaction w/ halogen (chlorine + butene)

dichlorobutane

CONDITION for alkene addition reaction w/ hydrogen

Ni catalyst

150 celsius

PRODUCT for alkene addition reaction w/ hydrogen

alkane

CONDITION for alkene addition reaction w/ water (hydration)

conc. phosphoric acid catalyst

300 celsius

60-70 atm

PRODUCT for alkene addition reaction w/ water (hydration)

alcohol

what is polymerisation

when several monomers join together to make a long chain polymer

how to make ethanol chemical method + conditions

hydration of ethene

300 celsius, 60-70 atm, conc. phosphoric acid catalyst

2 types of polymerisation and reactants

addition - alkene

condensation - diol, dicarboxylic acid

how to make ethanol biological way + conditions

fermentation of glucose

30 celsius, anaerobic, yeast

alcohol functional group

-OH

alcohol general formula

Cn H2n+1 OH

why might ethane have a lower b.p. than hexane

shorter main carbon chain

weaker intermolecular forces

less energy to overcome them

why might propan-1-ol have a higher b.p. than propan-3-ol

propan-1-ol has a flatter shape due to -OH position

more contact surface area

stronger intermolecular forces

more energy to overcome

how to make esters + condition + byproduct

alcohol + carboxylic acid

conc. sulfuric acid catalyst

water

carboxylic acid functional group

-COOH

carboxylic acid general formula

Cn-1 H2n-1 COOH

what kind of acid is carboxylic acid

weak (partially dissociates)

2 property of esters

fruity scent

low b.p

carboxylic acid ion that bonds with metals to form salts

___COO (everything minus the last H)

ester functional group

-COO-

what is the reverse reaction of esterification

hydrolysis

dehydration of ethanol to produce ethene CONDITION

hot aluminium oxide