Question

(Me) \({ }_{2} \mathrm{SiCl}_{2}\) on hydrolysis will produce: (a) \((\mathrm{Me})_{2} \mathrm{Si}(\mathrm{OH})_{2}\) (b) \((\mathrm{Me})_{2} \mathrm{~S} \mathrm{i}=\mathrm{O}\) (c) \(-\left[-\mathrm{O}-(\mathrm{Me})_{2} \mathrm{SI}-\mathrm{O}-\right]_{\mathrm{n}}-\) (d) \(\mathrm{Me}_{2} \mathrm{SiCl}(\mathrm{OH})\)

Short answer

The product of hydrolysis of \\( ext{(Me)}_{2} ext{SiCl}_{2} \\) is option (c): a polymer.

Step-by-step solution

Understanding Hydrolysis

Hydrolysis is a chemical reaction involving water, where water breaks bonds in a compound. In this case, the compound involved is \( ext{(Me)}_{2} ext{SiCl}_{2}\) which is a silicon compound.

Considering Possible Products

When \( ext{(Me)}_{2} ext{SiCl}_{2}\) undergoes hydrolysis, chlorine atoms are replaced by hydroxide (OH) groups. Thus, for each Cl removed, an OH can take its place. This suggests that initially, \( ext{(Me)}_{2} ext{Si(OH)}_{2} \) could be a possible product if all Cl ions are replaced by hydroxyl groups.

Examining Further Reactions

The compound \( ext{(Me)}_{2} ext{Si(OH)}_{2} \) is unstable. Under the right conditions, it can undergo a condensation reaction where water molecules are removed between \( ext{Si-OH} \) groups leading to the formation of Si-O-Si linkages. This results in a polymeric structure, making option (c) \( - ext{[-O-(Me)}_{2} ext{Si}- ext{O-]}_{n}- \), a more likely product.

Finalizing the Answer

Based on the steps and chemical behavior of silicon compounds, the likely product from the hydrolysis of \( ext{(Me)}_{2} ext{SiCl}_{2} \) is the polymer \( - ext{[-O-(Me)}_{2} ext{Si}- ext{O-]}_{n}- \). Therefore, option (c) is the correct choice.

Key concepts

Chemical Reaction

A chemical reaction is a process where substances, known as reactants, are transformed into different substances called products. These transformations involve the breaking and forming of chemical bonds. In the context of silicon compound hydrolysis, the chemical reaction involves water and a silicon compound. The reactants in this exercise are water and ext{(Me)}_{2} ext{SiCl}_{2}, a dichlorodimethylsilane. The water molecules break the silicon-chlorine bonds, allowing new silicon-oxygen bonds to form. Through the course of the reaction, chlorine atoms in the compound are replaced by hydroxide groups, represented by OH. This process is a quintessential example of hydrolysis. Eventually, these transformations can lead to further reactions, underlining the dynamic nature of chemical reactions. They do not just stop at initial product formation, especially with reactive substances like silicon compounds.

Silicon Compound

Silicon compounds are chemical compounds that include silicon and other elements. Silicon, a metalloid, forms a vast array of compounds, ranging from simple silicon oxides to complex silicones. Silicon is most famously known for its role in forming Si-O bonds, like in this exercise with the hydrolysis of ext{(Me)}_{2} ext{SiCl}_{2}. This compound consists of a silicon center with two methyl ( ext{Me}) groups and two chlorine ( ext{Cl}) atoms. When such compounds undergo hydrolysis, they exhibit versatile chemistry. This can lead to forming OH groups, eventually making a bridge structure known as a siloxane bond. The possibility of forming polymers from these compounds makes them highly valuable in industries, especially in manufacturing silicones used in various applications like lubricants and sealants.

Polymerization

Polymerization is the process of linking smaller molecules called monomers into larger, repeating structures known as polymers. In the case of silicon compound hydrolysis, the intermediate ext{(Me)}_{2} ext{Si(OH)}_{2} acts as the precursor for polymer formation. The ext{Si-OH} groups from each unit can react, leading to the elimination of water and the formation of ext{Si-O-Si} linkages. This condensation reaction is a stepwise polymerization process, eventually leading to the formation of long siloxane chains. Siloxane polymers are valued for their stability, flexibility, and resistance to extreme conditions, making them ideal for use in silicones. This example highlights the complex yet fascinating nature of chemical transformations and the formation of new functional materials.

Hydrolysis

Hydrolysis is a crucial chemical reaction where water is used to cleave bonds in molecules, thereby splitting them. In this process, water mainly serves two purposes: it breaks the existing bonds and incorporates its components (H and OH) into the resultant product. In our given example, ext{(Me)}_{2} ext{SiCl}_{2} undergoes hydrolysis, where water attacks and breaks silicon-chlorine bonds. This initial reaction produces ext{(Me)}_{2} ext{Si(OH)}_{2} by replacing Cl atoms with OH groups. However, this compound is not stable and readily rearranges to eliminate water, eventually forming a polymeric siloxane structure ( -[-O-(Me)}_{2} ext{Si}- ext{O-]}_{n}-). Hydrolysis reactions are prevalent in various scientific fields and are essential in both natural biochemical processes and industrial applications. They highlight the transformative power of water in chemical reactions, showcasing how simple molecules can drive complex chemical transformations.