organics

Question 1

Alkanes

Answer 1

• Consist of only hydrogen and carbon
• Only single bonds
• CnH2n+2
• Colourless
• Insoluble
• As carbon chain increases, BP increases
• Reactions are slow and require UV light / sunlight

Question 2

Alkenes

Answer 2

• Only carbon and hydrogen
• Atleast 1 double bond
• CnH2n
• Colourless compounds
• Low melting point and boiling point
• Insoluble in water
• Geometric isomers
• Cis: the halogens are on same bottom
• trans: halogens opposite each other
• Occur because carbon atoms joined by the double bond are unable to rotate around the
  double bond
• Alkenes undergo reaction readily with halogens
• Addition reactions occur faster than substitution reactions
• Alkenes can undergo addition reactions followed by substitution reactions if UV light is present
• Alkene + Hydrogen Halide -> form 1 thing, double bond broken
• Alkenes + Steam (catalyst) (high pressure) -> produce alcohol, double bond broken

Question 3

Distinguishing if alkane or Alkene

Answer 3

• Bromine
• Alkene w/ bromine turns colourless
• Alkane w/ bromine stays orange

Question 4

Alcohols

Answer 4

• BP of alcohol is higher than Alkene and Alkane due to hydrogen bonds & dispersion forces b/w
  molecules where Alkane only has dispersion forces
• Longer the chain, higher the BP due to added dispersion forces for every inc. in chain ( inc. in #
  of electrons)
• As molecular mass increases, solubility decreases

Question 5

Alcohol -> Aldehyde

Answer 5

R-CHO

• where CHO must be on ends
• something-al
• Always forms 2H+ and 2e

Both prepared by MNO4 or Dichromate

Question 6

Alcohol -> Carboxylic Acid

Answer 6

• R-COOH
• where COOH must be on ends
• something-oic acid
• need water on reactant side -> forms 2H+ and 2e from aldehyde
• need water on reactant side -> forms 4H+ and 4e from alcohol
• Both prepared by MNO4 or Dichromate

Question 7

Carboxylic Acid

Answer 7

• Are weak acids
• Acid strength decreases as chain increases
• Soluble in water due to hydrogen bonding b/w acid molecule and water molecule
• Each carboxylic acid has OH and O group to form hydrogen bonding w/, more soluble than
  alcohol w/ similar mass
• Hydrogen bonds form b/w carboxylic acid molecules
• Have higher M.P and B.P compared to other organic molecules
• Formation of dimers, where H matches with O from another and O matches from H of another

Question 8

Keytones

Answer 8

• Found within the chain and never on the ends

- C(O)

Question 9

Esters

Answer 9

• Formed between carboxylic acid and alcohol
• -COO-
• Formed in presence of acid catalyst eg. sulfuric acid
• naming is alkyl group + acid oate
• Drawing: Carboxylic Acid Chain - COO - Alcohol chain + H2O
• Can be converted back with to original reactants with acid w/ warming
• Called hydrolysis

Question 10

Amines

Answer 10

• Amines
• -NH2
• Polar
• Hydrogen bonding
• Weaker than Alcohols
• Lower molecular mass is usually soluble in water
• As chain increases, solubility decreases due to non-polar hydrocarbon dominating
• Weak base

Question 11

• Amino Acids

Answer 11

• contain amine + COOH
• Attached to same carbon
• Amino acids are amphoteric, at high pH levels COOH donates its H+ to form COO-
• Low pH amine accepts to become NH3
• At room temp, all solids
• High MP and BP similar to ionic
• Soluble in water

Question 12

Soaps

Answer 12

• Contain 1 hydrophobic tail and a hydrophillic head
• non polar = hydrophobic tail,
• polar = hydrophillic head
• eg. grease stain on shirt, the hydrophobic tail attacks the stain.
• > with the heads budding out of the stain
• > Washing machine shakes to embed more soap molecules under it
• > Polar heads help pull the grease out due to forming ion - dipole bonds w/ the water
• > Grease stain removed
• > Grease stain surrounded by a cage of polar heads to keep the stain out

-> downside is high in Mg2+ and Ca2+ in hard water, causing a yellow tinge precipitate to form

Question 13

Detergents

Answer 13

• Detergents are alkylbenzenesulfonates
• Dont form precipitates
• hydrophobic group attached to benzene ring
• > SO3- on otherside
• acts same as soap but doesnt precipitate

Question 14

Proteins

Answer 14

Amino Acids in a chain,

• Carboxylic group attach with amide of another amino group
• Expels water
• N attaches to COO to replace the H gone to water
• > peptide link

Question 15

Silicones

Answer 15

Si-O-Si-O-Si-O chains

- expels water