Question

Orthosilicic acid on dehydration gives (1) silicon (2) silica gel (3) quartz (4) crystalline forms

Short answer

Silica gel

Step-by-step solution

- Understand the Compound

Orthosilicic acid is a weak acid with the formula \( H_4SiO_4 \). It commonly forms in aqueous systems.

- Determine the Dehydration Product

When orthosilicic acid undergoes dehydration, it loses water molecules. This process typically leads to the formation of silica.

- Identify the Correct Option

Among the given options, silica can exist in different forms such as silica gel and quartz. However, silica gel is the product of orthosilicic acid's dehydration.

Key concepts

Orthosilicic Acid

Orthosilicic acid, with the chemical formula \( H_4SiO_4 \), is a weak and relatively unstable acid found in aqueous environments. It plays a crucial role in geological and biological processes. Orthosilicic acid is significant because it serves as a precursor to various silica-based materials, like silica gel and quartz.
Understanding its behavior in water is essential for grasping its role in different chemical reactions.

To explain in more detail: When orthosilicic acid is in solution, it can easily lose water molecules, which leads to a process called dehydration. This reaction is fundamental in forming solid silica compounds from the dissolved acid.

Key points to remember:

• Formula: \( H_4SiO_4 \)
• Weak acid, present in aqueous solutions
• Precursor to various forms of silica

Silica Gel

Silica gel is a form of silicon dioxide \( SiO_2 \) that typically appears as a granular, porous material. It is mainly recognized for its excellent moisture-absorbing properties, making it useful as a desiccant to control humidity and prevent spoilage.
Silica gel is produced from the dehydration of orthosilicic acid.

The dehydration reaction involves the removal of water molecules, transforming orthosilicic acid into silica gel. This process can happen naturally or be induced in industrial settings for commercial applications.

Key characteristics of silica gel:

• Highly porous and granular
• Excellent moisture absorber
• Formed by the dehydration of orthosilicic acid

Dehydration Reaction

A dehydration reaction is a type of chemical reaction where water molecules are eliminated from the reactant. This kind of reaction is crucial in transforming inorganic and organic substances.
In the case of orthosilicic acid, the dehydration reaction plays a vital role. When orthosilicic acid \( H_4SiO_4 \) loses water molecules (\( H_2O \)), it converts into silica. This can result in different forms of silica, including silica gel and quartz.

The overall dehydration reaction can be summarized with the following simplified equation:
\[ H_4SiO_4 \rightarrow SiO_2 + 2H_2O \]
Dehydration reactions are important in various chemical manufacturing processes and environmental systems as they often lead to more stable products.

Key aspects of dehydration reactions:

• Involves the loss of water
• Transforms orthosilicic acid into silica
• Leads to the formation of stable compounds