Question

Select correct statement: (a) \(\mathrm{GeO}_{2}, \mathrm{SnO}_{2}\) and \(\mathrm{PbO}_{2}\) are all acidic oxides. (b) Oxides of carbon family \(\left(\mathrm{MO}_{2}\right)\) are all networ soids with octahedral coordination. (c) Silicon dioxide (silica) is a network solid with terahedral coordination and is a giant molecule. (d) None of these.

Short answer

The correct statement is (c).

Step-by-step solution

Evaluate GeO2, SnO2, and PbO2

GeO2 and SnO2 are acidic oxides, but PbO2 is amphoteric, meaning it can react with both acids and bases. Hence, statement (a) is incorrect.

Analyze Oxides of Carbon Family

Oxides of the carbon family, such as SiO2 (silicon dioxide), do not form octahedral structures. Instead, they often form tetrahedral network structures, as in SiO2. Hence, statement (b) is incorrect.

Review Silicon Dioxide Structure

Silicon dioxide (SiO2) is known for its tetrahedral structure and forms a network solid known as quartz. It is indeed a giant covalent structure or molecule based on repeating units of tetrahedral \( ext{SiO}_4\). Hence, statement (c) is correct.

Conclude the Correct Option

After evaluating all statements: (a) is incorrect due to PbO2's amphoteric nature, (b) is incorrect due to the incorrect description of oxide structures in the carbon family, and (c) is correct with silicon dioxide described correctly. Thus, the correct statement is (c).

Key concepts

Acidic and Amphoteric Oxides

Oxides are compounds consisting of oxygen and another element. They can be classified as acidic, basic, or amphoteric based on their chemical behavior in reactions.

• Acidic Oxides: These react with bases to form salts and water. They are usually the oxides of non-metals like \( ext{SO}_2\) (sulfur dioxide), which reacts with water to form sulfuric acid.
• Amphoteric Oxides: These have the ability to react with both acids and bases, making them unique. \( ext{PbO}_2\), a member of the carbon family oxides discussed, can react with both types of substances. They show dual characteristics, being able to neutralize both acids and bases to form salts and water.

Understanding these properties helps in predicting the reactivity of an oxide in chemical processes and environments.

Carbon Family Oxides

The carbon family, also known as Group 14 on the periodic table, comprises of carbon (C), silicon (Si), germanium (Ge), tin (Sn), and lead (Pb). Their oxides feature some intriguing properties related to their chemical structure and bonding. - **Silicon Dioxide (SiO2):** It's perhaps the most well-known oxide in this family. It forms a strong three-dimensional network because of its tetrahedral arrangement of silicon atoms surrounded by oxygen atoms. - **Germanium Dioxide (GeO2) and Tin Dioxide (SnO2):** Both behave as acidic oxides, which tend to form when these elements bond with oxygen. - **Lead Dioxide (PbO2):** Interestingly, PbO2 exhibits amphoteric behavior, meaning it can engage in reactions characteristic of both acidic and basic oxides. These oxides are solid at room temperature and exhibit diverse chemical behaviors due to the bonding and structural differences among the different members of the carbon family.

Tetrahedral and Octahedral Coordination

Chemical compounds often possess distinct geometrical arrangements of atoms. The coordination number and geometry greatly influence the properties and reactions of a compound. - **Tetrahedral Coordination:** This is a structure where a central atom is bonded to four other atoms positioned at the corners of a tetrahedron. Silicon dioxide, for instance, features silicon atoms covalently bonded to four oxygen atoms in a repeating tetrahedral pattern, contributing to its rigidity and high melting point. - **Octahedral Coordination:** In contrast, this involves a central atom surrounded by six other atoms or groups, forming the shape of an octahedron. This setup is common in transition metal complexes but not typically observed in carbon family oxides. Understanding these coordination structures is essential to grasping why substances have certain physical and chemical properties. Specifically, it highlights the diversity of molecular shapes beyond the simple linear or angular structures traditionally taught in introductory chemistry.