Problem 187 - A Complete Resource Book in Chemistry for JEE Main

Question

Match the following $$ \begin{array}{ll} \hline \text { Column-I } & \text { Column-II } \\ \hline \text { (a) Peroxide } & \text { (p) } \mathrm{C}_{3} \mathrm{O}_{2} \\\ \text { (b) Superoxide } & \text { (q) } \mathrm{PbO}_{2} \\ \text { (c) Dioxide } & \text { (r) } \mathrm{KO}_{2} \\ \text { (d) Suboxide } & \text { (s) } \mathrm{H}_{2} \mathrm{O}_{2} \\ & \text { (t) } \mathrm{RbO}_{2} \end{array} $$

Step-by-Step Solution

Answer

(a)-(s), (b)-(r), (c)-(q), (d)-(p).

Step 1: Identify the Compounds

Examine the given compounds and match their general characteristics. - Peroxide: Compounds like hydrogen peroxide - Superoxide: Compounds that contain the O_2^(-1) ion, like KO_2 - Dioxide: Compounds with O_2 such as PbO_2 - Suboxide: Compounds with less oxygen than oxide, like C3O2.

Step 2: Match Peroxide

Identify which compound in Column-II is a peroxide. H2O2 is a known peroxide. So, (a) Peroxide matches with (s) H2O2.

Step 3: Match Superoxide

Identify the superoxide compounds. Superoxides contain the O_2^(-1) ion. Both KO2 and RbO2 fit this criterion, but since we have KO2 in Column-II, match (b) Superoxide with (r) KO2.

Step 4: Match Dioxide

Find which compound fits the dioxide category. PbO2 is a dioxide because it contains Pb with two oxygen atoms. Therefore, match (c) Dioxide with (q) PbO2.

Step 5: Match Suboxide

Identify the suboxide. C3O2 has the fewest oxygen atoms relative to the carbon it contains, so (d) Suboxide matches with (p) C3O2.

Key Concepts

Peroxide

Peroxides are special types of chemical compounds that contain an unusual oxygen-oxygen single bond. A well-known example of a peroxide is hydrogen peroxide, with the chemical formula \( \text{H}_2\text{O}_2 \). This specific structure allows peroxides to easily release oxygen, which is why they are often used as oxidizing agents.

Peroxides typically have the following characteristics:

• They contain a peroxy bond, which is represented as \(-\text{O}-\text{O}-\).
• The bond makes peroxides reactive, particularly in breaking down to release oxygen gas.
• Hydrogen peroxide, a common household disinfectant, is an often-cited example of a simple peroxide.

Understanding the peroxy bond is crucial, as this is what gives peroxides their unique properties compared to other oxygen-containing compounds.

Superoxide

Superoxides are compounds containing the \(\text{O}_2^{\ -1}\) ion. This means they have a bond between two oxygen atoms, but one has an added extra electro-negativity, which influences their reactivity. The superoxide ion is less stable and thus superoxides are often used in applications like organic degradation or in fuel cells.

Key points about superoxides:

• They are formed by the direct transfer of an electron to molecular oxygen, \(\text{O}_2\).
• Examples include compounds such as potassium superoxide \(\text{KO}_2\).
• They are good oxidizing agents and play a role in biological processes such as the breakdown of toxins.

In chemical reactions, superoxides behave quite differently from standard oxides or dioxides, making them interesting for both theoretical and practical chemistry studies.

Dioxide

A dioxide refers to a compound that contains two oxygen atoms per molecule. Unlike peroxides, dioxides have oxygen atoms that are bonded in a way that does not have the reactive peroxy bond. Lead dioxide, \(\text{PbO}_2\), is a typical example of such a compound.

Characteristics of dioxides include:

• They generally have the formula \(\text{XO}_2\), where \(\text{X}\) is an element like lead or carbon.
• Dioxides often act as oxidizing agents due to the presence of multiple oxygen atoms, that's shared in a stable structure with another element.
• They can participate in redox reactions.

These properties make dioxides important for industrial applications, where they often serve as catalysts or bleaching agents.

Suboxide

Suboxides are compounds with less oxygen compared to a typical oxide. They are relatively rare and have unusual stoichiometry. For example, \(\text{C}_3\text{O}_2\), also known as carbon suboxide, is a lesser-known type of suboxide.

Important aspects of suboxides:

• They often contain an unconventional ratio of oxygen to the central atom compared to typical oxides.
• Suboxides exhibit unique chemical and physical properties.
• They are often intermediates in the oxidation processes or other chemical transformations.

Understanding suboxides and their role in chemistry can provide insights into unusual oxidation states and bonding scenarios. This makes them an intriguing topic for those interested in advanced studies.