Organic synthesis

Question 1

Describe how to set up heating under refulx

Answer 1

• Clamp a round bottom flask at its neck to a retort stand.
  -Add solution to the flask aswell as anti buming granules.
• apply grease to the ground glass joints and connect a condensing tube ontop of the flask rotating to create a secure seal.
  -Attach the water inlet tube to the bottom of the liebeg condensor, outlet at the top.
• Add a bunsen burner or water bath underneath to heat the solution.

Question 2

What should not be added to a heating under reflux setup?

Answer 2

Stopper at the top of the condensor, pressure build could explode the apparatus.

Question 3

Describe how to setup a distillation.

Answer 3

• Clamp a round bottomed flask by its neck to a retort stand.
• Add the solution to the flask.
• Add a still head adapter to the flask (gearsing the joints), and add a thermometer on top of the still head.
• Add a condensor to the still head (greasing joints), making sure the condensor slopes down from the still head.
• Add a water inlet tube to the bottom of the condensor and outlet at the top.
• Add a reciever to the condensor and clamp the receiver at its neck.
• Place a flask underneath the reciever to collect the distillate.
• Add a bunsen burner or water bath underneath the round bottom flask.

Question 4

What 3 steps are done to purify an organic product?

Answer 4

• Separating funnel rid of aqueous (H2O) layer.
• Drying with anhydroys salt.
• redistilling the organic product

Question 5

Describe the first step of preparing organic products
(non acid)

Separating layers

Answer 5

separation of layers:
- Place mixture into a separating funnel and close it with a stopper.
- Invert funnel back and forth to mix.
- Wait for layers to reform.
- Add water to the separating funnel, whichever layer increases in volume is the aqueous/ water layer and the other is organic.
- Place a flask underneath the separating funnel to remove the lower layer, repeat using a separate funnel for the upper layer, discarding the aqueous layer.

Question 6

Describe the first step of purifying organic products
(If an acid may be present)

Separating layers

Answer 6

Repeat regular separation of organic product from aqueous layer however:
- Add aqueous sodium carbonate to the mixture in the separation funnel before inverting the funnel to mix.
- Also once mixed invert the funnel upsidedown and turn the tap to release the CO2 produced.
- separate away the remaining aqueous sodium carbonate as usual.

Question 7

Describe the second step of purifying organinc products

Drying organic product

Answer 7

Drying organic product (removal or remaining H2O) :
- Add organic liquid into a conical flask.
- Using a spatula add the anhydrous salt whilst gently stiring.
- Place a stopper in the flask and wait for 10 minutes.
- If solid is clumped together add more anhydrous salt and mix
- Once the solid is evenly disperesed, decant the liquid (not solid) into another flask.

Question 8

Describe the third step of purifying an organic solid and why?

redistillation

Answer 8

Redistillation:
- Distill again with a narrower boiling range
Due to the fact that some organic impurities may still remain.

Question 9

Name the different Anhydrous salts used for drying products and their intended use

Answer 9

For drying hydrocarbons:
- Anhydrous calcium carbonate (CaCl2)
For General drying:
- Anhydrous Magnesium Sulfate (MgSO4)
-Anhydrous Calcium Sulfate ( CaSO4)