Question

You look at the label on a container of shortening and see the words "hydrogenated vegetable oil." this means that during processing, the number of carbon–carbon double bonds in the oil was decreased. what is the result of decreasing the number of double bonds?

Answer 1

• Increase in melting point;
• Trans- arrangements of side chains around double bonds that remains in the hydrogenated fat.

Explanation:

Vegetable oil contain significantly more double bonds than animal fat such as butter does. Unlike carbon-carbon single bonds, structures connected to carbon-carbon double bonds are unable to rotate around the bonding axis. As a result, molecules rich in double bonds aren't as malleable or stack as tightly as those with a small number of double bonds do. The spacy molecular configuration hinders the formation of intermolecular forces, such that in nature in comparison with animal fats, vegetable oils tend to demonstrate lower melting points.

Hydrogenating vegetable oils reduce the number of double bonds per molecule while attaching extra hydrogen atoms to carbon atoms that used to form double bonds. This process would increase the strength of intermolecular interaction, hence raising the melting point.

The hydrogenation process does not necessary convert all double bonds to single bonds; some double bonds remains in the molecule, preventing the rotation of structures on their sides. Double bonds in unprocessed fatty acids tend to be of the cis- configuration, with hydrogen atoms connected to the same side of the carbon-carbon double bond. The high temperature involved in the hydrogenation process (around 90 degrees Celsius) can trigger the flipping of atoms connected to these double bonds to produce trans- fatty acids with hydrogen atoms bonded to opposite sides of the double bond.

Answer 2

• Increase in melting point;
• Trans- arrangements of side chains around double bonds that remains in the hydrogenated fat.

Explanation:

Vegetable oil contain a larger ratio of double bonds among all its carbon-carbon bonds than animal fat such as butter does. Unlike carbon-carbon single bonds, structures connected to carbon-carbon double bonds are unable to rotate around the bonding axis. As a result, molecules rich in double bonds aren't as malleable or stack as tightly as those with a smaller number of double bonds do. The spacy molecular configuration hinders the formation of intermolecular forces, such that in nature in comparison with animal fats, vegetable oils tend to demonstrate lower melting points.

Hydrogenating vegetable oils reduce the number of double bonds per molecule while attaching extra hydrogen atoms to carbon atoms that used to form double bonds. This process would increase the strength of intermolecular interaction, hence raising the melting point.

The hydrogenation process does not necessary convert all double bonds to single bonds; some double bonds remains in the molecule, preventing the rotation of structures on their sides. Double bonds in naturally-occuring fatty acids tend to be of the cis- configuration, with hydrogen atoms connected to the same side of the carbon-carbon double bond. The high temperature involved in the hydrogenation process (around 90 degrees Celsius) can trigger the flipping of atoms connected to these double bonds to produce trans- fatty acids with hydrogen atoms bonded to opposite sides of the double bond.