Question

For all the reactions, identify the reaction type and name the products formed.

1) How would you prepare ethoxyethane from ethene? Provide equations/reactions

2) How would you prepare propanoic acid from prop-1-ene? Provide equations/reactions

3) Place the following organic molecules in order of increasing boiling points: butane, butan-2-one, butanoic acid, and butan-2-ol. Justify your answer.

Answer 1

1) Ethoxyethane can be prepared from ethene by the reaction of ethene with ethanol in the presence of a catalyst such as sulfuric acid. This is an example of an addition reaction.

Equation:

C2H4 + C2H5OH → C4H10O (ethoxyethane)

2) Propanoic acid can be prepared from prop-1-ene by the reaction of prop-1-ene with potassium permanganate (KMnO4) in the presence of water. This is an example of an oxidation reaction.

Equation:

CH2=CHCH3 + 2KMnO4 + 3H2O → CH3CH2COOH (propanoic acid) + 2MnO2 + 2KOH

3) The order of increasing boiling points is: butane < butan-2-ol < butan-2-one < butanoic acid.

Butane is a nonpolar molecule and has only weak London dispersion forces between its molecules, so it has the lowest boiling point.

Butan-2-ol has a polar hydroxyl group (-OH) which allows for hydrogen bonding between its molecules, increasing its boiling point compared to butane.

Butan-2-one has a polar carbonyl group (C=O) which also allows for dipole-dipole interactions between its molecules, increasing its boiling point compared to butan-2-ol.

Butanoic acid has a polar carboxyl group (-COOH) which allows for hydrogen bonding between its molecules, making it the most polar and highest boiling compound among the given options.