Question

The reaction \(\left(\mathrm{CH}_{3}\right)_{3} \mathrm{C}-\mathrm{Br} \stackrel{\mathrm{H}_{2} \mathrm{O}}{\longrightarrow}\left(\mathrm{CH}_{3}\right)_{3} \mathrm{C}-\mathrm{OH}\) is (a) addition reaction (b) substitution reaction (c) free radical reaction (d) elimination reaction

Short answer

This is a substitution reaction.

Step-by-step solution

Identify Reaction Type

Look at the given chemical equation. There is a molecule, \((\mathrm{CH}_{3})_{3}\mathrm{C}-\mathrm{Br}\), which reacts with water. The \(-\mathrm{Br}\) group is being replaced by an \(-\mathrm{OH}\) group, converting it into \((\mathrm{CH}_{3})_{3}\mathrm{C}-\mathrm{OH}\).

Definition of Reaction Types

Understand the definitions of different types of reactions: - *Addition Reaction*: Two or more molecules combine to form a single product. - *Substitution Reaction*: An atom or a group in a molecule is replaced by another atom or group. - *Free Radical Reaction*: A type of reaction that involves free radicals. - *Elimination Reaction*: A reaction where elements of the reactant are removed to form an additional bond.

Match with Substitution Reaction

In this case, the reaction involves replacing a \(-\mathrm{Br}\) group with an \(-\mathrm{OH}\) group. This exchange of one group for another fits the definition of a *substitution reaction*.

Key concepts

Chemical Reaction Types

Chemical reactions come in various forms. Each type defines how the substances interact and what products they yield. Understanding these types helps predict the outcomes of reactions. The most common types include addition, substitution, free radical, and elimination reactions.

• **Addition Reaction**: Features two or more reactants combining to form a complex product. They are often seen in organic chemistry with unsaturated molecules.
• **Substitution Reaction**: Involves one atom or group in a molecule being swapped for another. This is typical in halogens and certain organic compounds.
• **Free Radical Reaction**: Centers around molecules with unpaired electrons. These reactions are spontaneous and usually require energy input to proceed.
• **Elimination Reaction**: Characterized by the removal of a smaller molecule from a larger one, often forming double or triple bonds in the process.

Recognizing these reaction types provides a foundation for understanding chemical transformations in organic chemistry and beyond.

Organic Chemistry

Organic chemistry is a branch of chemistry that studies the structure, properties, and reactions of organic compounds, which contain carbon. At its heart, it is about how carbon and hydrogen atoms arrange themselves in various formations and how they react to form new substances.
The reason organic chemistry is vital is due to carbon's unique properties. Carbon atoms can form stable bonds with many different elements, including other carbon atoms, allowing for a vast diversity of compounds.
Some common reactions in organic chemistry include:

• Substitution reactions, where one atom or group replaces another.
• Addition reactions, where atoms are added to a double or triple bond.
• Elimination reactions, which remove atoms from a molecule to form new bonds.

Learning organic chemistry is essential for fields such as biochemistry, pharmaceuticals, and material science, where the creation and modification of complex organic molecules play a key role.

Nucleophilic Substitution

Nucleophilic substitution is a type of substitution reaction particularly relevant in organic chemistry. It involves the substitution of a leaving group by a nucleophile, which is a molecule that donates an electron pair to an electrophile. In this process, a chemical bond is formed while another is broken. This highlights the interaction between electron-rich nucleophiles and electron-deficient electrophiles.
There are two main types of nucleophilic substitution reactions:

• **S_N1 Reactions**: These are unimolecular, involving a two-step mechanism. First, the leaving group departs, creating a carbocation. Then, the nucleophile attacks, forming the final product.
• **S_N2 Reactions**: These are bimolecular and occur in a single concerted step, where the nucleophile attacks the substrate at the same time the leaving group exits.

Nucleophilic substitution reactions are pivotal in organic synthesis. They allow for the introduction of functional groups into a molecule, crucial for manufacturing pharmaceuticals, agrochemicals, and polymers.