Problem 132 - A Complete Resource Book in Chemistry for JEE Main

Question

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

Step-by-Step Solution

Answer

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

Step 1: Understand the Matching Terms

The exercise involves matching the terms in Column-I with their appropriate chemical formulas in Column-II. Each term in Column-I describes a type of oxide or related compound.

Step 2: Peroxide Identification

Identify 'peroxide' from the options. Peroxides contain the peroxide ion, \( \text{O}_2^{2-} \). Among the given options, \( \text{H}_2\text{O}_2 \) is hydrogen peroxide, containing the peroxide ion. Match: (a) with (s).

Step 3: Superoxide Identification

Identify 'superoxide'. Superoxides contain the superoxide ion, \( \text{O}_2^{-} \). The compounds \( \text{KO}_2 \) and \( \text{RbO}_2 \) are known to be superoxides.Match: (b) with (r) or (t) (both fit).

Step 4: Dioxide Identification

Identify 'dioxide'. Dioxides have formulas where two oxygen atoms are bound to another element, typically as \( \text{O}_2^{2-} \) anions. \( \text{PbO}_2 \) is lead dioxide.Match: (c) with (q).

Step 5: Suboxide Identification

Identify 'suboxide'. Suboxides often have lower oxygen content than expected. \( \text{C}_3\text{O}_2 \) is carbon suboxide because oxygen is less compared to typical oxide proportions.Match: (d) with (p).

Key Concepts

Peroxides

Peroxides are a unique class of chemical compounds distinguished by the presence of the peroxide ion, which is denoted as \( \text{O}_2^{2-} \). This diatomic ion is bound together with a single covalent bond between the two oxygen atoms. Peroxides are usually associated with simple or complex cations to form stable compounds. A common example that many are familiar with is hydrogen peroxide, \( \text{H}_2\text{O}_2 \), which contains this peroxide linkage.

• Peroxides have a characteristic feature where they tend to decompose, often releasing oxygen gas. This is used in applications such as bleaching and disinfection.
• The peroxide bond is relatively weak, making these compounds reactive and sometimes hazardous if not handled correctly.
• Peroxides are found naturally as well as synthetically and play important roles in various industrial processes.

When dealing with peroxides, it is important to understand their chemical behavior due to their tendency to decompose and, in some cases, to be explosive.

Superoxides

Superoxides are another intriguing class of oxygen compounds. These compounds contain the superoxide ion, \( \text{O}_2^{-} \), which features an unusual charge distribution. The presence of only one negative charge between the two oxygen atoms imparts this ion with distinctive chemical properties.

• Superoxides are less stable than normal oxides and often require specific conditions to remain stable.
• They are primarily used in the chemical industry as oxidizing agents and in the field of organic synthesis.
• In terms of their formation, alkali metals are known to form superoxides, such as potassium superoxide \( \text{KO}_2 \) and rubidium superoxide \( \text{RbO}_2 \).

The reactive nature of superoxides makes them useful, but also mandates careful handling and storage. Their ability to produce oxygen upon reaction with water is often utilized in applications like life-saving oxygen-generating devices.

Dioxides

Dioxides represent a group of compounds where two oxygen atoms are bonded typically to a single metal or non-metal center. The term "dioxide" can refer to substances with various bonding arrangements, such as covalent or ionic.

• A classical example is carbon dioxide \( \text{CO}_2 \), a covalent compound well known for its role in the Earth's carbon cycle and as a greenhouse gas.
• Dioxides like lead dioxide (\( \text{PbO}_2 \)), are used as strong oxidizing agents and are significant in battery technology, such as in lead-acid batteries.
• Dioxides often exhibit unique behaviors due to the structural arrangement of oxygen atoms around another element, influencing their reactivity patterns and commercial uses.

Understanding the chemical structure and properties of different dioxides is crucial in fields ranging from environmental science to engineering.

Suboxides

Suboxides are compounds where the ratio of metal (or non-metal) to oxygen is lower than in typical oxides. This unconventional ratio often results in fascinating properties that differ from both ordinary oxides and peroxides.

• One of the most frequently discussed examples is carbon suboxide \( \text{C}_3\text{O}_2 \), known for its distinct structure featuring a chainlike arrangement of carbon and oxygen atoms.
• These compounds can exhibit intriguing physical properties, such as unique conductivity or colorations, due to the presence of unusual bonding structures.
• Suboxides are often intermediate compounds during the synthesis or decomposition of more stable oxides.

While suboxides might not be as widely encountered in everyday applications, their distinct characteristics make them a topic of interest in research, particularly in materials science and chemistry.