Question

the contents on a box of cupcakes lists partially hydrogenated soybean oil. partial hydrogenation of soybean oil has what effect?
○ it produces fatty acid salts.
○ it decreases the percent of unsaturation that is present.
○ it hydrolyzes the triacylglycerol.
○ it increases the number of fatty acids present.
○ it decrease the number of hydrogen atoms present on the molecule.

Explanation:

1. Analyze Option 1: Fatty acid salts are produced by saponification (reaction of fats with strong bases), not hydrogenation. So this is incorrect.
2. Analyze Option 2: Partial hydrogenation involves adding hydrogen to unsaturated fatty acid chains (which have double bonds). Adding hydrogen converts some double bonds (unsaturated sites) to single bonds, thus decreasing the percent of unsaturation. This matches the process of partial hydrogenation.
3. Analyze Option 3: Hydrolysis of triacylglycerol breaks it into fatty acids and glycerol, while hydrogenation is an addition reaction, not hydrolysis. So this is incorrect.
4. Analyze Option 4: Partial hydrogenation adds hydrogen atoms, it does not increase the number of fatty acids (fatty acids are part of the triacylglycerol structure; hydrogenation doesn't create new fatty acids). So this is incorrect.
5. Analyze Option 5: Partial hydrogenation adds hydrogen atoms to the molecule (to reduce double bonds), so it increases, not decreases, the number of hydrogen atoms. So this is incorrect.

Answer:

B. It decreases the percent of unsaturation that is present.