Chemistry 2.7 by Holly Jones https://padlet.com/hol_cjones/gmfcnslz3ql7 Made with a taste for adventure en-us 2019-01-30 12:12:16 UTC 2025-04-25 16:12:21 UTC hello@padlet.com https://padlet-assets.s3.amazonaws.com/icons/Soccerball.png Making an Ester hol_cjones https://padlet.com/hol_cjones/gmfcnslz3ql7/wish/325795154 1) Water bath - 250ml beaker ~50°C 
2) Pear Flask-
  • 25ml CH3COOH
  • 10ml C2H5OH
  • 10 drops H2SO4
  • ~5 anti-bumping granules
3) Put into water bath for 15 mins
]]> 2019-01-30 12:12:25 UTC https://padlet.com/hol_cjones/gmfcnslz3ql7/wish/325795154 Testing for alcohols - traffic light test 317683 https://padlet.com/hol_cjones/gmfcnslz3ql7/wish/325795155 Reagents: Potassium dichromate(VI) & dilute sulfuric acid
Observations: Colour change from orange to green

Cr2O72- (orange) ions change to Cr3+ (green) ions.]]> 2019-01-30 12:12:25 UTC https://padlet.com/hol_cjones/gmfcnslz3ql7/wish/325795155 Alcohol Oxidation 317683 https://padlet.com/hol_cjones/gmfcnslz3ql7/wish/325795156
  • Oxidation is the addition of oxygen atoms or removal of hydrogen atoms.
  • Reduction is the removal of oxygen atoms or addition of hydrogen atoms.
    • ethanol(primary) + [O] (oxidising agent) --> ethanal(AL - aldehyde)
    C2H5OH + [O] --> CH3CHO + H2O
    ethanal + [O] --> ethnic acid(carboxylic acid)
    CH3CHO + [O] --> CH3COOH
    --> along the arrow - H+(aq) & K2Cr2O7

    Primary alcohol --> Aldehyde --> Carboxylic acid
    Secondary alcohol --> Ketone

    We can use dilute Potassium dichromate(VI) solution acidified with dilute sulfuric acid.

    ]]>     2019-01-30 12:12:25 UTC https://padlet.com/hol_cjones/gmfcnslz3ql7/wish/325795156     Alcohol Dehydration hol_cjones https://padlet.com/hol_cjones/gmfcnslz3ql7/wish/325795157 C2H5OH --> C2H4 + H2O
    Catalyst = Concentrated H2SO4
    Example
    CH3CH2CH2OH --> CH3CHCH2 + H2O
    Propan-1-ol --> Propene + Water]]>     2019-01-30 12:12:25 UTC https://padlet.com/hol_cjones/gmfcnslz3ql7/wish/325795157     Testing for carboxylic acids 317683 https://padlet.com/hol_cjones/gmfcnslz3ql7/wish/325795158 Reagent: Sodium hydrogen carbonate(NaHCO3) or sodium carbonate(Na2CO3)
    Observation: effervescence (CO2 produced)]]>     2019-01-30 12:12:25 UTC https://padlet.com/hol_cjones/gmfcnslz3ql7/wish/325795158     Biological route of making ethanol 317683 https://padlet.com/hol_cjones/gmfcnslz3ql7/wish/325795159 Photosynthesis: 6CO2 + 6H2O --> C6H12O6 + 6O2
    Fermentation(yeast): C6H12O6 --> 2C2H5OH + 2CO2
    Combustion: C2H5OH + 3O2--> 2CO2 + 3H2O

    Fermentation is an enzyme catalysed reaction, converting sugars to ethanol. YEast is often used.
    Bio fuels are fuels produced from a biological source.

    ]]>     2019-01-30 12:12:25 UTC https://padlet.com/hol_cjones/gmfcnslz3ql7/wish/325795159     Fractional Distillation of Ethanol hol_cjones https://padlet.com/hol_cjones/gmfcnslz3ql7/wish/325795160 2019-01-30 12:12:25 UTC https://padlet.com/hol_cjones/gmfcnslz3ql7/wish/325795160 Making Ethanol hol_cjones https://padlet.com/hol_cjones/gmfcnslz3ql7/wish/325795161 H2C=CH2(g) + H20(g) ⇌ C2H5OH (g)
    ΔH = -45kJmol-1
    Reactants = Ethene + Steam
    Product = Ethanol
    Catalyst = Phosphoric Acid (H3PO4)
    Conditions = 300 ºC , 60-70 atm
    • Catalyst used to speed up reaction by decreasing the activation energy, therefore allowing more product to be produced
    • High pressure used - 2:1 moles of gas therefore PoE shifts —> More product produced because the forward reaction is favoured
    • High temperature used - Forward reaction = Exothermic therefore if you cool the reaction the PoE shifts —> and products increase, however the rate decreases. 300ºC is a compromise temperature because its hot enough to give a decent rate but cool enough to let the PoE shifts —>
    ]]>     2019-01-30 12:12:25 UTC https://padlet.com/hol_cjones/gmfcnslz3ql7/wish/325795161     Example of an Ester hol_cjones https://padlet.com/hol_cjones/gmfcnslz3ql7/wish/325795162 2019-01-30 12:12:25 UTC https://padlet.com/hol_cjones/gmfcnslz3ql7/wish/325795162 Esters hol_cjones https://padlet.com/hol_cjones/gmfcnslz3ql7/wish/325795163 Carboxylic acid + Alcohol ⇌  Ester + Water
    Forwards reaction = Esterification
    Backwards reaction Hydrolysis ]]>     2019-01-30 12:12:25 UTC https://padlet.com/hol_cjones/gmfcnslz3ql7/wish/325795163     Benefits and Drawbacks of Biofuel hol_cjones https://padlet.com/hol_cjones/gmfcnslz3ql7/wish/325795165 Benefits
    • Produces less CO2 than greenhouse gases
    • Renewable
    • Easy to source- formed from many different sources eg. manure, crops and plants
    • Creates jobs as biofuel industry grows
    Drawbacks
    • Plants are produced in other countries therefore they have to be transported- transport uses fossil fuels
    • May not have suitable conditions to grow plants in the UK
    • Ethical issue- using land in poor countries to grow plants for fuel rather than food
    • May increase water demand
    • May require fertilisers- dangerous to environment
    ]]>     2019-01-30 12:12:25 UTC https://padlet.com/hol_cjones/gmfcnslz3ql7/wish/325795165