Hydrogenation facts for kids

Hydrogenation is a special chemical trick where hydrogen is added to other chemical compounds. Think of it like adding a missing piece to a puzzle! This process is often used with a type of chemical called an alkene.

Alkenes are found in many things, like vegetable oils. These oils are usually liquid and can go bad quickly. To make them more solid and last longer, like in shortening or margarine, hydrogen is added to the alkenes. This changes them into alkanes, which are more stable and solid at room temperature. A special helper called a catalyst is needed to make this reaction happen. Sometimes, this process can create something called trans fats.

Hydrogenation isn't just for food! It's also used to make other important chemicals. For example, hot hydrogen gas can be mixed with nitrogen gas under high pressure with a nickel catalyst to create ammonia gas. Ammonia is a very important chemical used in fertilizers and many other products.

What is Hydrogenation?

Hydrogenation is a chemical reaction that adds hydrogen (H₂) to an organic compound. An organic compound is a chemical that contains carbon atoms. This process usually happens when there's a special helper called a catalyst present. Catalysts are substances that speed up a chemical reaction without being used up themselves.

How it Works

Imagine a chemical compound that has "empty spots" where more hydrogen atoms could fit. Hydrogenation fills these spots. For example, alkenes are chemicals that have a "double bond" between two carbon atoms. This double bond can be broken, and a hydrogen atom can attach to each carbon, turning the alkene into an alkane. Alkanes have only "single bonds" between their carbon atoms and are generally more stable.

Hydrogenation in Food

One of the most common uses of hydrogenation is in the food industry. It helps turn liquid oils into more solid fats.

Making Spreads and Shortening

Many liquid vegetable oils contain alkenes. These oils can spoil quickly because the double bonds in alkenes are less stable. To make products like margarine and shortening, hydrogen is added to these oils. This changes the liquid alkenes into solid alkanes. The result is a fat that is more solid at room temperature and lasts longer on the shelf.

Understanding Trans Fats

When oils are hydrogenated, sometimes a type of fat called a trans fat can be formed. These are different from the natural fats found in foods. Scientists have learned that eating too many trans fats is not good for your health. Because of this, many food companies have changed how they make their products to reduce or remove trans fats.

Other Uses of Hydrogenation

Hydrogenation is a versatile process used in many different industries, not just food.

Making Ammonia

One important example is the production of ammonia (NH₃). Ammonia is a gas used to make fertilizers, cleaning products, and many other chemicals. To make ammonia, nitrogen gas (N₂) and hydrogen gas (H₂) are reacted together under very high pressure and temperature. A catalyst, often nickel or iron, helps this reaction happen efficiently. This process is known as the Haber-Bosch process.

In the Chemical Industry

Hydrogenation is also used to make many other chemicals. It can change the properties of different substances, making them useful for new purposes. For example, it can be used to make alcohols, amines, and other organic compounds that are building blocks for plastics, medicines, and other materials.

Images for kids

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  Mechanism for the hydrogenation of a terminal alkene using Wilkinson's catalyst.

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  The transition state of two transfer-hydrogenation reactions from ruthenium-hydride complexes onto carbonyls

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  Selective hydrogenation of the less hindered alkene group in carvone using a homogeneous catalyst (Wilkinson's catalyst).

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  Partial hydrogenation of phenylacetylene using the Lindlar catalyst.

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  Hydrogenation of an imine using a Raney nickel catalyst, a popular heterogeneous catalyst.

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  Partial hydrogenation of a resorcinol derivative using a Raney-Nickel catalyst.

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  Hydrogenation of maleic acid to succinic acid.

See also

In Spanish: Hidrogenación para niños