Question

Complete the hydrogenation reaction. $$ \mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}=\mathrm{CH}_{2}+\mathrm{H}_{2} \longrightarrow $$

Short answer

\(\mathrm{CH}_3\mathrm{CH}_2\mathrm{CH}_2\mathrm{CH}=\mathrm{CH}_2 + \mathrm{H}_2 \longrightarrow \mathrm{CH}_3\mathrm{CH}_2\mathrm{CH}_2\mathrm{CH}_2\mathrm{CH}_3\)

Step-by-step solution

Understanding the reaction

Hydrogenation is the chemical reaction between a compound and hydrogen (H2). In the context of organic chemistry, it typically involves the addition of hydrogen across double bonds in unsaturated hydrocarbons, such as alkenes, to yield saturated hydrocarbons.

Identifying the reactants

The reactant hydrocarbon is pent-1-ene ((CH3CH2CH2CH=CH2), which has a double bond between the fourth and fifth carbon atoms. The other reactant is hydrogen gas (H2).

Addition of hydrogen to the double bond

The hydrogenation reaction will add a molecule of hydrogen (H2) across the double bond of pent-1-ene, turning the unsaturated alkene into a saturated alkane.

Writing the product of the reaction

The double bond in the alkene will be broken, and a hydrogen atom will be added to each carbon atom that was part of the double bond. This results in the product: pentane (CH3CH2CH2CH2CH3).

Completing the hydrogenation reaction equation

The complete hydrogenation reaction is: \[\mathrm{CH}_3\mathrm{CH}_2\mathrm{CH}_2\mathrm{CH}=\mathrm{CH}_2 + \mathrm{H}_2 \longrightarrow \mathrm{CH}_3\mathrm{CH}_2\mathrm{CH}_2\mathrm{CH}_2\mathrm{CH}_3\]

Key concepts

Organic Chemistry

Organic chemistry is a fascinating and diverse field focusing on the study of carbon-containing compounds and their properties, structures, and reactions. While carbon may seem simple, its ability to form strong covalent bonds with other elements, particularly hydrogen, oxygen, and nitrogen, as well as with other carbon atoms, leads to an amazing variety of organic molecules.

In organic chemistry, these carbon-based molecules often consist of long chains or rings which are referred to as the 'backbone' and can have various functional groups attached. A functional group is a specific arrangement of atoms within a molecule that is responsible for the characteristic chemical reactions of that molecule.

Importance of Organic Chemistry

Organic chemistry is not only fundamental for understanding life processes but is also the foundation of various industries including pharmaceuticals, petrochemicals, and polymers. The discipline plays a crucial role in drug development, food chemistry, and the design of molecular machines and new materials.

Saturated and Unsaturated Hydrocarbons

Hydrocarbons are compounds composed exclusively of carbon and hydrogen. They are categorized into two main groups: saturated and unsaturated hydrocarbons.

Saturated hydrocarbons, also known as alkanes, have single bonds between carbon atoms and are saturated with hydrogen because they contain the maximum number of hydrogen atoms possible. They have a general formula of \( C_nH_{2n+2} \). Saturated hydrocarbons are known for their lack of reactivity and are found in substances like propane and methane, commonly used as fuels.

On the other hand, unsaturated hydrocarbons contain double or triple bonds between carbon atoms. They can be further divided into alkenes, with one or more double bonds, and alkynes, with one or more triple bonds. Unsaturated hydrocarbons are more reactive than their saturated counterparts due to the presence of these multiple bonds, which are sites for chemical reactions.

Examples and Applications

Unsaturated hydrocarbons, such as ethene (\( C_2H_4 \)) and propene (\( C_3H_6 \)), are essential in the production of plastics and other synthetic materials. Their ability to undergo reactions such as polymerization makes them valuable in manufacturing various commercial products.

Chemical Reactions

Chemical reactions are processes that involve the transformation of one set of chemical substances to another. Reactants are converted into products through the breaking and forming of chemical bonds, with reaction conditions like temperature, pressure, and catalysts influencing the process.

Hydrogenation is a specific type of chemical reaction where hydrogen is added to another compound, often an unsaturated hydrocarbon. It is widely used to convert unsaturated fats to saturated fats in the food industry, as well as to produce saturated hydrocarbons in the petrochemical industry.

The reaction requires a catalyst, typically a metal such as palladium, platinum, or nickel, which facilitates the addition of hydrogen atoms to the multiple bonds of the unsaturated hydrocarbons, thereby 'saturating' the molecule. This process not only changes the chemical structure but can also affect the physical properties. For example, hydrogenated oils become more solid and shelf-stable.

Understanding Reaction Mechanisms

Studying the mechanisms behind chemical reactions enables scientists and engineers to design processes that are more efficient, sustainable, and environmentally friendly, highlighting the importance of chemistry in the advancement of technology and industry.