chemistry homework

Lab: Synthesis of Esters

 Complete the following assignment and submit your work to the dropbox.

Before you upload your file, ensure your name appears on the first page of your document.

Since you are doing this course virtually, and will not be working with actual chemicals during this laboratory, the procedure is given in order for you to be aware of the process that would be followed in a laboratory setting.

Material

Chemicals

acetic acid (glacial), ethanol, sulphuric acid (concentrated), salicylic acid, butanoic acid, methanol, 1-pentanol, propionic acid, benzoïc acid, octanol, isoamyl alcohol

Apparatus:

beaker, round flask, pipette, pipetter, electronic balance, wire gauze, hot plate, boiling chips, support stand, clamp

Safety

· Safety goggles and a lab apron should always be worn when working with chemicals.

· This lab will be performed using small quantities of chemicals (micro-scale chemistry).

· Your teacher will dispense the concentrated sulphuric acid.

· Use the wafting technique to identify smells in the lab. Never smell the opening of the flask directly!

Procedure

1. Prepare a hot bath of boiling water as follows: place about 200 mL of water in a 600 mL beaker; add 3 boiling chips to smooth the boiling; place the beaker on a hot plate and boil.

2. In a 250 mL round flask, add 5 mL of one of the available organic alcohols.

3. Add 5 mL or 3 g of one of the available carboxylic acids.

4. Carefully add 2 mL of concentrated sulphuric acid to the flask, as a catalyst.

5. Mix the contents by gently swirling the flask.

6. Secure the flask to a support stand using a clamp.

7. Place the flask in the boiling water bath.

8. After 10 minutes, remove the flask and let it cool.

9. Add 15 mL of distilled water to the flask to dilute the ester and to soften its smell.

10. Using the appropriate technique, identify the odour of the substance produced by this reaction. Do not smell the opening of the flask directly!

11. Note your observations (odour).

12. Repeat steps 2 to 11 for three other combinations of alcohols and acids.

Results

· Give the names of all the compounds included in each reaction.

· Give the balanced chemical equation for each reaction.

Use The Esters Odours Table (below) to note the odour you would expect to smell in the lab, for each ester you produce.

Odours of Various Esters

Ester

Odour

Ethyl acetate Ethyl benzoate Ethyl butanoate Ethyl cinnamate Ethyl decanoate Ethyl formiate Ethyl hexanoate Ethyl isobutanoate Ethyl isopropionate Ethyl isovalerate Ethyl phenylacetate Ethyl propionate Ethyl salicylate Methyl acetate Methyl anthranilate Methyl benzoate Methyl butanoate Methyl heptanoate Methyl isobutanoate Methyl isopropionate Methyl phenylacetate Methyl propionate Methyl salicylate Pentyl acetate Pentyl butanoate Octyl acetate Isopentyl acetate Benzyl acetate Butyl butanoate Isobutyl acetate Isobutyl propionate Isopentyl propionate Isopentyl acetate

Glue/fruit Fruit Pineapple/roses (peach) Honey, peach Grape Rum Pineapple, banana Apple Apple Apple Honey Strawberry Wintergreen (mint) Berries Grape Fruit Apple, banana Berries, iris Apple, pineapple, apricot Apple Honey, jasmine Berries, rum Wintergreen (mint) Banana, pear (honey) Apricot Orange Banana Jasmine Pineapple Raspberry Rum Pineapple Orange

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Conclusion

Briefly state the results for the laboratory, in general. This should be no more than two sentences.

Please ensure that your lab report contains the following: · title page · purpose · results · conclusion