organic

• molecules :)

  • acyl chlorides

  general formula: [R]COCl

  suffix: ~oyl chloride

  • what are acyl chlorides made out of?

    acyl chlorides consist of a double bond of carbon to an oxygen atom at the edge of the molecule, this carbon atom is also bonded to a chlorine atom

  • what reactions can acyl chlorides undergo?

    • substitution reactions

    • substitution to amides

      Reagent: conc NH3 (alcoholic)

    • substitution/hydrolysis to carboxylic acids

      Reagent: H2O

  • how are acyl chlorides formed?

    acyl chlorides can be formed in substitution reactions from carboxylic acids using the reagent thinoyl chloride - SOCl2

  • alcohols

  general formula: [R]OH

  suffix: ~ol

  • what are alcohols made out of?

    carbon molecules bonded to an OH molecule

  • what reactions can alcohols undergo?

    • elimination reactions

    • elimination/dehydration/condensation to alkenes

      Reagent: concentrated H2SO4

    • substitution reactions

    • substitution to haloalkanes

      Reagent: concentrated HCl or SOCL2

    • substitution/esterification/condensation to esters

      Reagent: carboxylic acid + concentrated H2SO4

    • oxidation reactions

    • total oxidation to carboxylic acids

      Reagent: MnO4-/H+ or Cr2O72-/H+

      Conditions: reflux

    • 1° partial oxidation to aldehydes

      Reagent: MnO4-/H+ or Cr2O72-/H+

      Conditions: warm gently and distill

      Observations: orange Cr2O72- reduces to green Cr3+ ion

      or purple MnO4- reduces to colourless Mn2+ ions

    • 1° full oxidation to carboxylic acids

      Reagent: Cr2O72-

      Conditions: heat under reflux

    • 2° oxidation to ketones

      Reagent: KMnO4/H+ or K2Cr2O7/H+

  • how are alcohols formed?

    • addition/hydrogenation from alkenes

    Reagent: dilute H2SO4

    • substitution from haloalkanes

    Reagent: KOH (aqueous) or NaOH (aqueous)

    • substitution/acid or base hydrolysis from esters

    Reagent: H2O

    A hydrolysis reaction uses water to split a large organic molecule into
    smaller organic molecules. The C=O gains –OH from water, and the C–O
    gains –H from water. Both acidic and basic hydrolysis require heat under
    reflux. Acidic hydrolysis requires a dilute acid (e.g. dil. H2SO4), whereas
    basic hydrolysis requires a dilute base (e.g. dil. NaOH).

    • reduction from aldehydes and ketones

    Reagent: NaBH4

  • aldehydes

  general formula: [R] CHO

  suffix: ~al

  • what are aldehydes made out of?

    aldehydes consist of a carbon double bonded to an oxygen atom at the edge of a molecule, this carbon atom is also bonded to a hydrogen atom.

    they are more reactive then ketones

  • what reactions can aldehydes undergo?

    • oxidation to carboxylic acids

    Reagent: MnO4-/H+ or Cr2O72-/H+ or tollens (Ag+) or Fehlings (Cu2+) or benedicts (Cu2+)

    • reduction to alcohols

    Reagent: NaBH4

  • how are aldehydes formed?

    • partial oxidation from 1° alcohols

    Reagent: MnO4-/H+ or Cr2O72-/H+ and distillation

  • alkenes

  general formula: CnH2n

  suffix: ~ene

  • what are alkenes made out of?

    alkenes are unsaturated hydrocarbons that primarily consist of hydrogen and carbon and contain a double carbon bond

  • what reactions can alkenes undergo?

    • oxidation to diols

    • what conditions are required?

      Reagent: MnO4-/H+

    • how are they formed?

      many small monomer unsaturated alkenes bond together to form a long polymer chain

    • addition reactions

    • addition/hydrogenation to alcohols

      • what conditions are required?

      Reagent: dilute H2SO4

      Catalyst: nickel/platinum

    • addition/hydrogenation/bromination/chlorination to haloalkanes

      • what conditions are required?

      Reagent: HBr, HCl, Br2

    • symmetrical vs asymmetrical alkene addition

      when undergoing addition reactions, the hydrogen atom will bond to the carbon already bonded to the highest number of hydrogen atoms - the rich get richer - to create a major product. if this does not occur, a minor product is formed.

  • how are alkenes formed?

    • elimination reactions

    • elimination from haloalkanes

      • what conditions are required?

      Reagent: KOH (alcoholic)

    • elimination/dehydration/condensation from alcohols

      • what conditions are required?

      Reagent: concentrated H2SO4

  • alkynes

  general formula: CnH2n-2

  suffix: ~yne

  • amides

  general formula: [R]CONH2

  suffix: ~amide

  • what are amides made out of?

    amides consist of a carbon double bonded to oxygen at the edge of the molecule, this carbon is also bonded to an NH2 ammonia group

  • what reactions can amides undergo?

  • how are amides formed?

    • substitution reactions

    • substitution from carboxylic acids

      Reagent: NH3 and heat

    • substitution from acyl chlorides

      Reagent: concentrated NH3 (alcoholic)

    • from esters

  • amines

  general formula: [R]NH2

  suffix: amine

  • what are amines made out of?

    a carbon chain bonded to a NH2 ammonia molecule

    they have higher boiling points then alkanes, but lower than alcohols

  • how are amines formed?

    amines can be formed though substitution reactions from haloalkanes. these reactions need the reagent of concentrated NH3 (alcoholic) to occur

  • carboxylic acids

  general formula: [R]COOH

  suffix: ~oic acid

  • what are carboxylic acids made out of?

    carboxylic acids consist of a carbon double bonded to oxygen at the edge of the molecule, this carbon atom is also bonded to an OH hydroxide molecule

  • what reactions can carboxylic acids undergo?

    • substitution to acyl chlorides

    Reagent: SOCl2

    • substitution to amides

    Reagent: NH3 and heat

    • substitution/esterification/condensation to esters

    Reagent: alcohols and H2SO4

  • how are carboxylic acids formed?

    • substitution reactions

    • substitution/hydrolysis from acyl chlorides

      Reagent: H2O

    • oxidation reactions

    • total oxidation from alcohols

      Reagent: MnO4-/H+ or Cr2O72-/H+ or tollens (Ag+) or Fehlings (Cu2+) or benedicts (Cu2+)

    • oxidation from ketones

      Reagent: MnO4-/H+ or Cr2O72-/H+ under reflux

  • diols

  • how are diols formed?

    oxidation from alkenes, with reagent MnO4-/H+

  • esters

  general formula: [R]COO[R]

  suffix: yl/oate

  • what are esters made out of?

    esters consist of a carbon double bonded to an oxygen molecule in the molecule, this carbon is also bonded to another oxygen atom

  • what reactions can esters undergo?

    esters can undergo reactions with NH3 to form amides

    or hydrolysis to form alcohols

  • how are esters formed?

    esters are formed by substitution/esterification/condensation of alcohols and carboxylic acids with the reagent of concentrated H2SO4, the water molecule is removed, forcing the forward reaction

  • ketones

  general formula: [R]CO[R]

  suffix: ~one

  • what are ketones made out of?

    ketones consist of a carbon atom double bonded to an oxygen atom at the centre of a molecule

    they are less reactive than aldehydes

  • what reactions can ketones undergo?

    ketones can undergo reduction reactions with the reagent NaBH4 to form alcohols

  • how are ketones formed?

    ketones are formed by the oxidation of 2° alcohols with the reagent KMnO4-/H+ or K2Cr2O7/H+

  • haloalkanes

  general formula: [R][X]

  suffix: ~ane

  • what are haloalkanes made out of?

    a carbon chain bonded to a bromine, chlorine or iodine molecule

  • what reactions can haloalkanes undergo?

    • substitution reactions

    • substitution to alcohols

      Reagent: KOH (alcoholic)

    • substitution to amides

      Reagent: KOH(aq) or NaOH(aq)

    • elimination to alkenes

    Reagent: concentrated NH3 (alcoholic)

  • how are haloalkanes formed?

    • addition/halogenation/bromination/chlorination reactions

    Reagent: HBr, HCl, Br2

    • substitution reactions

    Reagent: conc HCl or SOCl2

• isomerism :)

  • structural

  same molecular formula, different structural formula

  • chain

    the chain is branched differently

  • positional

    the position of the functional group differs

  • functional

    the functional group has changed

  • stereoisomerism

  same molecular formula, atoms occupy different positions in space

  • geometric

    occurs due to restricted rotation of C double bond, cis/trans

  • optical

    occurs when molecules have a chiral centre as the carbon is bonded to four different atoms or molecules, producing two non-superimposable mirror images

    How to tell enantiomers apart?

    The enantiomers can be distinguished based on their ability to rotate plane
    polarised light. One enantiomer will rotate the plane-polarised light to the
    left, while the other enantiomer will rotate the plane-polarised light to the
    right.

    When there are equal amounts of both enantiomers, the solution is called racemic and the light will not be rotated

• reactions & reagents :)

  • reagents:

  • lucas reagent

    the lucas reagent is used to identify 1°, 2° and 3° alcohols, it is ZnCl2 + conc HCl

    3° alcohols - turns cloudy immediately

    2° alcohols - turns cloudy within 3-5 minutes

    1° alcohols. - no change, solution remains colourless

    alcohol + HCl —ZnCl2—> haloalkane + water

  • damp litmus paper

    • amine

    damp red paper turns blue

    • carboxylic acid

    damp blue paper turns red

    • amide

    no change

    • acyl chloride

    damp blue paper turns red

  • universal indicator

    • amine

    turns blue (basic)

    • carboxylic acid

    orange or yellow (acidic)

    • amide

    no change

    • acyl chloride

    red (strong acid)

  • heat with acidified Cr2O72-

    • alcohol (primary)

    partial oxidation reaction, solution goes from orange to green as an aldehyde forms, if a full oxidation reaction occurs, the solution goes from purple to colourless and a carboxylic acid is formed

    • alcohol (secondary)

    oxidation reaction occurs and solution changes from orange to green as a ketone forms

    • alcohol (tertiary)

    no reaction

    • aldehyde

    oxidation reaction, solution goes from purple to colourless as carboxylic acid forms

    • ketone

    no reaction

    • acyl chloride

    vigorous exothermic reaction

  • heat with acidified MnO4-

    • alcohol (primary

    partial oxidation reaction, solution goes from purple to colourless as aldehyde forms, if a full oxidation reaction occurs, a carboxylic acid will form

    • alcohol (secondary)

    oxidation reaction occurs and solution changes colour from purple to colourless as a ketone forms

    • alcohol (tertiary)

    no reaction

    • aldehyde

    oxidation reaction, solution goes from purple to colourless as carboxylic acid forms

    • ketone

    no reaction

    • acyl chloride

    vigorous exothermic reaction

  • conc HCl

    • amine

    white cloud forms

  • Cu2+

    • amine

    complex ions forms with a deep blue colour

  • warm with fehling’s/benedict’s solution - used to distinguish aldehydes from ketones

    • aldehyde

    blue solution changes to a brick red precipitate

    • ketone

    no reaction, solution remains blue

  • tollen’s reagent & heat - used to distinguish aldehydes from ketones

    • aldehyde

    colourless solution forms silver mirror or black precipitate

    • ketone

    no reaction

  • NH3

    • acyl chloride

    white fumes given off

  • water

    • amines

    soluble

    • esters

    insoluble and form a visible layer on top as they are less dense

    • acyl chlorides

    vigorous exothermic reaction, fumes given off as carboxylic acid forms

  • reactions:

  • hydrolysis:

    A hydrolysis reaction uses water to split a large organic molecule into
    smaller organic molecules. The C=O gains –OH from water, and the C–O
    gains –H from water. Both acidic and basic hydrolysis require heat under
    reflux. Acidic hydrolysis requires a dilute acid (e.g. dil. H2SO4), whereas
    basic hydrolysis requires a dilute base (e.g. dil. NaOH).

  • molecules & reagents:

    • reflux

    The reflux process is used because it ensures that volatile
    molecules are contained when the reaction is heated

    As, it travels upwards, the vapour is condensed in the
    condenser, and drops back into the reaction mixture to be further
    oxidised

    • distillation

    Distillation separates organic molecules by evaporating
    and condensing molecules based on boiling points.

    • w/ water

    • amine with water

      eg: propanamine

      H3CCH2CH2NH2 + H2O → H3CCH2CH2NH3+ + OH-

    • acyl chloride with water

      eg: propanyl chloride

      CH3COCl + H2O → CH3COOH + HCl

    • carboxylic acid with water

      carboxylic acid + H2O → ← carboxylate ion + H3O+ (weak acids only partially dissociate)

      eg: propanoic acid

      C2H5COOH + H2O →← C2H5COO- + H3O+

    • oxidation of alcohols

    • partial oxidation of primary alcohol

      primary alcohol → aldehyde

      RCH2OH → RCHO + 2e + 2H+

      eg: propan-1-ol

      reagent: KMnO4

      C3H7OH → C3H6O + 2H+ + 2e

    • full oxidation of primary alcohol

      primary alcohol → carboxylic acid

      RCH2OH → RCOOH + 2e + 2H+

      eg: propan-1-ol

      reagent: KMnO4

      C3H7OH → C2H5COOH + 2H+ + 2e

    • oxidation of secondary alcohol

      secondary alcohol → ketone

      RCH2OH → RCOR + 2e+ 2H+

      eg: propan-2-ol

      reagent: KMnO4

      C3H7OH → C3H6O + 2H+ + 2e

    • aldehydes

    • silver mirror

      tollens reagent is reduced by aldehydes to form a silver metal

      Ag(NH3)2 + (aq) + e → Ag(s) + 2NH3(aq)

      the aldehyde is oxidised to form a carboxylic acid

      RCHO(aq) + 2OH- (aq) → RCOOH (aq) + H2O(l) + 2e

      eg: propanal in tollens

      CH3CH2CHO + Ag+ → RCOOH(aq) + Ag

    • fehlings/benedicts

      the blue aqueous copper ions are reduces by aldehydes to form a red insoluble solid

      2Cu2+ (aq) + 2OH-(aq) + 2e → Cu2O(s) + H2O(l)

condensation polymerisation:

small organic molecules join to make a large organic molecule, with the release of a small molecule (mainly H2O) for every amide link formed