Hydrogenation of fats:
A. Is a chemical reaction

B. Consists of addition of hydrogen at double bonds of unsaturated acyl groups

C. Is agitation of solid hydrogen, liquid oil and gaseous catalyst in a closed vessel

D. Mostly uses non-metallic compounds as catalyst

E. Permits conversion of liquid oils into plastic fats

Choose the correct answer from the options given below:

Correct option is B

· A. Is a chemical reaction: Hydrogenation is indeed a chemical reaction where hydrogen (H₂) is added to unsaturated fats (oils). This reaction occurs at the double bonds of unsaturated fatty acids to convert them into saturated fatty acids.
· B. Consists of addition of hydrogen at double bonds of unsaturated acyl groups: During hydrogenation, hydrogen atoms are added across the double bonds of unsaturated acyl groups in oils (vegetable oils or liquid fats). This addition of hydrogen makes the oils more saturated, turning them into solid or semi-solid fats.
· E. Permits conversion of liquid oils into plastic fats: The conversion of liquid oils (e.g., vegetable oils) into semi-solid or plastic fats (like margarine) is one of the main purposes of hydrogenation. This process increases the melting point of the oil, making it more solid at room temperature.
Information Booster:
1. Hydrogenation as a Chemical Reaction (A): Hydrogenation is a chemical reaction in which hydrogen gas (H₂) is added to unsaturated fatty acids, specifically at the carbon-carbon double bonds of the fatty acid chains. In its simplest form, this reaction involves the breaking of a double bond in the fatty acid chain, allowing a hydrogen atom to attach to each of the carbon atoms involved in the bond. This process reduces the degree of unsaturation in the fat, leading to the formation of saturated fatty acids. This is why hydrogenation is commonly used to convert liquid oils (which are rich in unsaturated fatty acids) into solid fats like margarine, butter, or shortening.
2. Addition of Hydrogen to Double Bonds (B): The primary feature of hydrogenation is the addition of hydrogen atoms to the double bonds in the unsaturated acyl groups (fatty acids). Unsaturated fats, like those found in vegetable oils, contain one or more double bonds between carbon atoms. Hydrogenation "saturates" these double bonds by adding hydrogen, converting them into single bonds. This increases the degree of saturation of the fat, making it more stable and less prone to oxidation, which extends the shelf life of products made from hydrogenated fats. This process is particularly useful in food production, where the texture and consistency of fats (such as margarine and shortening) are critical.
3. Conversion into Plastic Fats (E): When liquid oils undergo hydrogenation, they are partially or fully converted into plastic fats. These fats are semi-solid at room temperature, which is a desirable property for certain food products. Hydrogenation provides the ability to manipulate the texture and consistency of fats, making them more suitable for different uses in the food industry. For instance, margarine and shortening are hydrogenated oils that provide the right consistency for baking, cooking, and spreading.
Additional Knowledge (Incorrect Options):
· Option C:Agitation of solid hydrogen, liquid oil, and gaseous catalyst in a closed vessel: This option is incorrect because hydrogenation does not require solid hydrogen or gaseous catalysts. In fact, hydrogen gas (H₂) is bubbled through the liquid oil in the presence of a metallic catalyst (e.g., nickel). The process usually takes place in a high-pressure vessel, but the hydrogen is in gaseous form, not solid. The role of the catalyst is to speed up the reaction and facilitate the hydrogenation without being consumed in the process. Solid hydrogen and gaseous catalysts are not involved in the standard hydrogenation process.
· Option D:Mostly uses non-metallic compounds as catalyst: This is incorrect because the hydrogenation process typically uses metallic catalysts. Nickel is the most commonly used metallic catalyst, although sometimes platinum or palladium can also be used. Non-metallic compounds are generally ineffective for catalyzing hydrogenation reactions. Metallic catalysts are chosen because of their ability to efficiently facilitate the addition of hydrogen to unsaturated bonds, making the process much faster and more economical.