Unit 14: Applications of Organic Chemistry
D: Investigate organic chemistry reaction to gain skills in preparative organic chemistry
- Preparation of a compound with carbonyl functional group
Alcohol-partial Oxidation
Oxidation of ethanol
Oxidation can be oxidised via burning in either oxygen or air. Additionally, Microbial oxidation refers
to the reaction of ethanol with oxygen in the air to be able to create ethanoic acid. Initially, ethanol
undergoes oxidation to be able to create acetaldehyde, which can be distinguished by its pleasant
aroma. Moreover, water is also generated during this reaction. The resulting mixture is then allowed
to further undergo further oxidation. Once the oxidation process is finished, acetaldehyde is
transformed into ethanoic acid, which has a more pungent smell like vinegar. (Bell-Young, 2018).
Additionally, after heating the ethanol with acidified sodium dichromate (VI), it can then undergo
partial oxidation to be able to create ethanal, CH3 CHO, or complete oxidation to be able to form
ethanoic acid, CH3 COOH. Furthermore, to be able to achieve complete oxidation, the reagents are
heated under reflux for an extended period to ensure complete reaction as well as minimize
substance loss through evaporation. The resulting product is then purified via distillation. For partial
oxidation, the reagents are reacted in a distillation apparatus to be able to purify the volatile aldehyde
before complete oxidation can happen.
Risk assessment:
,
,Equipment:
- Test tubes
- Safety googles
- Anti-bumping granules
- Measuring cylinders (25cm3)
- Thermometer (-10 to 110 degree)
- Pear-shaped/ round bottom flask (50cm3) (Quick fit apparatus)
- Still head
- Receiver
- Liebig condenser and tubing
- Bunsen burner
- Wide-necked funnel
- Quick fit adaptor for the thermometer
, - Water bath
- Pipette
- 250 cm cubed beaker consisting of ice (ice water bath)
- Retort stands, bosses as well as clamps
- Ethanol
- Sodium dichromate (VI)
- 2.0ml dm3 aqueous sulfuric acid
- Sodium carbonate solid
- 0.100mol dm3 aqueous potassium dichromate
Method (partial oxidation of ethanol)
- First 2.0g of the sodium dichromate (VI)-2- water is added in to the pear-shaped/ round-
bottomed flask utilizing the funnel
- 20cm cubed 2.0mol dm3 of sulfuric (VI) acid is then carefully and slowly added in to the pear-
shaped/round bottomed flask utilizing the funnel
- Few anti-bumping granules are then added in the flask and swirled slowly until the solid
begins to dissolve
- The solution is then cooled by swirling the flask in an ice bath for around 2 to 3 minutes, until
the solution begins to be ice cold (10 degrees Celsius)
- After this, 0.5cm cubed of ethanol is slowly and carefully added into the flask dropwise while
swirling the ice water
- The mixture is then swirled in ice water for a while, while also monitoring the reaction
temperature utilizing a thermometer (here the temperature will begin to increase)
- Once reached the maximum temperature, the steps are repeated including a second 0.5
cubed of ethanol
- After this, the flask is then removed from the ice water and dried with paper towel (water left
on the outside)
- The flask is then left to warm at room temperature
- The flask is then clamped from the neck and the quick fit apparatus is arranged in a distillation
setup
- The condenser is then turned on for the water flow
- The reaction mixture is then heated in a water bath, over a hot plate
- Once 2-3 cm cubed of cubed of clear colourless distillate has been distilled off in a test tube,
the test tube is stopped, and the boiling point of the distillate is then recorded
Boiling point of the distillate 35 degrees Celsius
Images of the practical:
D: Investigate organic chemistry reaction to gain skills in preparative organic chemistry
- Preparation of a compound with carbonyl functional group
Alcohol-partial Oxidation
Oxidation of ethanol
Oxidation can be oxidised via burning in either oxygen or air. Additionally, Microbial oxidation refers
to the reaction of ethanol with oxygen in the air to be able to create ethanoic acid. Initially, ethanol
undergoes oxidation to be able to create acetaldehyde, which can be distinguished by its pleasant
aroma. Moreover, water is also generated during this reaction. The resulting mixture is then allowed
to further undergo further oxidation. Once the oxidation process is finished, acetaldehyde is
transformed into ethanoic acid, which has a more pungent smell like vinegar. (Bell-Young, 2018).
Additionally, after heating the ethanol with acidified sodium dichromate (VI), it can then undergo
partial oxidation to be able to create ethanal, CH3 CHO, or complete oxidation to be able to form
ethanoic acid, CH3 COOH. Furthermore, to be able to achieve complete oxidation, the reagents are
heated under reflux for an extended period to ensure complete reaction as well as minimize
substance loss through evaporation. The resulting product is then purified via distillation. For partial
oxidation, the reagents are reacted in a distillation apparatus to be able to purify the volatile aldehyde
before complete oxidation can happen.
Risk assessment:
,
,Equipment:
- Test tubes
- Safety googles
- Anti-bumping granules
- Measuring cylinders (25cm3)
- Thermometer (-10 to 110 degree)
- Pear-shaped/ round bottom flask (50cm3) (Quick fit apparatus)
- Still head
- Receiver
- Liebig condenser and tubing
- Bunsen burner
- Wide-necked funnel
- Quick fit adaptor for the thermometer
, - Water bath
- Pipette
- 250 cm cubed beaker consisting of ice (ice water bath)
- Retort stands, bosses as well as clamps
- Ethanol
- Sodium dichromate (VI)
- 2.0ml dm3 aqueous sulfuric acid
- Sodium carbonate solid
- 0.100mol dm3 aqueous potassium dichromate
Method (partial oxidation of ethanol)
- First 2.0g of the sodium dichromate (VI)-2- water is added in to the pear-shaped/ round-
bottomed flask utilizing the funnel
- 20cm cubed 2.0mol dm3 of sulfuric (VI) acid is then carefully and slowly added in to the pear-
shaped/round bottomed flask utilizing the funnel
- Few anti-bumping granules are then added in the flask and swirled slowly until the solid
begins to dissolve
- The solution is then cooled by swirling the flask in an ice bath for around 2 to 3 minutes, until
the solution begins to be ice cold (10 degrees Celsius)
- After this, 0.5cm cubed of ethanol is slowly and carefully added into the flask dropwise while
swirling the ice water
- The mixture is then swirled in ice water for a while, while also monitoring the reaction
temperature utilizing a thermometer (here the temperature will begin to increase)
- Once reached the maximum temperature, the steps are repeated including a second 0.5
cubed of ethanol
- After this, the flask is then removed from the ice water and dried with paper towel (water left
on the outside)
- The flask is then left to warm at room temperature
- The flask is then clamped from the neck and the quick fit apparatus is arranged in a distillation
setup
- The condenser is then turned on for the water flow
- The reaction mixture is then heated in a water bath, over a hot plate
- Once 2-3 cm cubed of cubed of clear colourless distillate has been distilled off in a test tube,
the test tube is stopped, and the boiling point of the distillate is then recorded
Boiling point of the distillate 35 degrees Celsius
Images of the practical:
