Answered>Order 19348

  1. The lowest boiling point of the esters you synthesized is 101°C. How does this apply to the reason you should not use a water bath that is boiling when removing the petroleum ether?
  2. What is the purpose of adding sodium bicarb to the test tubes? Why is it bubbling?
  3. What is the point of using salt water when your pour the contents of a test tube into the beaker? (hint: think about the molecular structure of the esters and what happens when salt dissolves in water)

This was the directions for the lab:

  1. Obtain goggles and wear them. Many of the chemicals used in this lab are dangerous. In particular acetic anhydride and concentrated sulfuric acid can cause painful burns.
  2. Start a water bath.In a 400 mL beaker add about 200 mL of tap water
  3. Place it on a hotplate and set the temperature to approximately 3-5 marks on the temperature dial.
  4. You may use a thermometer to check that the temperature is around 70°C mark. Make sure the thermometer does not touch the bottom of the beaker however.
  5. Obtain four large test tubes and label them A, B, C and D.
  6. Place 15 drops of acetic anhydride in each test tube.
  7. Place 3 drops of concentrated sulfuric acid in each test tube as well and mix them thoroughly by tapping on the tube for a couple of minutes. Make sure you do not place your finger over the hole and began shaking. This is a quick way to give yourself an acid burn on your hand. You should also make sure you’re not shaking the test tube in someone’s direction. If you’re uncertain as to how to mix this without spilling it ask your instructor for a demonstration.
  8. Cool the test tubes in an ice bath for a couple of minutes.
  9. Carefully add 13 drops of an alcohol to each test tube making sure that you only have one type of alcohol in each test tube and you do not repeat any alcohols.
  10. Place the test tubes in your 70°C water bath for approximately 15 min.
  11. Cool the reaction mixture in an ice bath and very carefully at 1 mL of cold distilled water.
  12. Slowly! Slowly, add drop wise 1 mL of sodium bicarbonate solution. This step will bubble be careful. Keep adding sodium bicarbonate solution until no more bubbling occurs.

Congratulations you have now made your first organic compounds. The esters are in your test tubes and just need to be purified.

  1. Fill a 150 mL beaker about half way with saturated NaCl. 
  2. Pour one of your test tube mixtures into the beaker and stir gently with a glass rod.
  3. Smell the beaker by wafting it to your nose (do not stick your face into the beaker).
  4. Make notes on what you think it smells like.
  5. Repeat this process with the remaining ester products.
  6. All solutions can be poured down the drain with running water.
 
"Not answered?"
Get the Answer