Final answer:
Partial hydrogenation is the chemical addition of hydrogen to the double bonds of alkenes, to convert them into more saturated compounds like those used in the food industry to create semi-solid fats. The correct answer is c. chemical addition of hydrogen atoms.
Step-by-step explanation:
Partial hydrogenation involves the chemical addition of hydrogen atoms to double bonds in unsaturated compounds to make them more saturated. Specifically, it is the process of adding hydrogen to the double bond of an alkene, like ethylene, to create a product that contains single C-C bonds, such as ethane. This process is commonly used in the food industry to convert liquid vegetable oils into semi-solid forms like margarine, which is achieved by transforming some of the double bonds in polyunsaturated vegetable oils.
The correct option from the given choices would be c. chemical addition of hydrogen atoms. During partial hydrogenation, not all of the double bonds may be hydrogenated, resulting in the creation of trans-fats in some cases. This partial hydrogenation can modify the physical properties of fats, such as melting point and texture, to resemble those of butter.
A typical hydrogenation reaction uses a catalyst such as platinum or nickel and may require high pressure of hydrogen gas to proceed effectively. The process yields products with reduced numbers of double bonds, turning polyunsaturated compounds into partially or fully saturated compounds.