Problem 105 - A Complete Resource Book in Chemistry for JEE Main

Question

What are the products formed in the reaction of xenon hexafluoride with silicon dioxide? (a) \(\mathrm{XeO}_{3}+\mathrm{SiF}_{2}\) (b) \(\mathrm{XeOF}_{4}+\mathrm{SiF}_{4}\) (c) \(\mathrm{XeSiO}_{4}+\mathrm{HF}\) (d) \(\mathrm{XeF}_{2}+\mathrm{SiF}_{4}\)

Step-by-Step Solution

Answer

The correct products are (b) XeOF e{4} + SiF e{4} .

Step 1: Identify the reactants

The reactants in this reaction are xenon hexafluoride (XeF e{6} ) and silicon dioxide (SiO e{2} ). These will undergo a reaction to form new products.

Step 2: Understand the possible reactions

Xenon hexafluoride (XeF e{6} ) can react with silicon dioxide (SiO e{2} ) to produce a mix of compounds involving xenon, oxygen, and fluorine due to the nature of the compounds and the reactivity of the elements involved.

Step 3: Evaluate the chemical reaction possibilities

Consider the balanced equations that can result from the reaction of xenon hexafluoride and silicon dioxide. A typical outcome is the formation of XeOF e{4} (xenon oxytetrafluoride) and SiF e{4} (silicon tetrafluoride). This implies breaking SiO e{2} into SiF e{4} completely and forming XeOF e{4} from XeF e{6} .

Step 4: Evaluate the given options

Assess the given options to see which matches the logical products of the reaction: (a) XeO e{3} + SiF e{2} is incorrect due to the lack of corresponding reaction feasibility and products. (b) XeOF e{4} + SiF e{4} is correct and matches the expected product formation. (c) XeSiO e{4} + HF is incorrect as no HF forms under typical conditions. (d) XeF e{2} + SiF e{4} is incorrect due to mismatched anticipated products.

Key Concepts

Xenon Hexafluoride

Xenon hexafluoride (XeF\(_6\)) is a chemical compound where xenon is in a high oxidation state. This compound is unique because it's a rare example of a noble gas forming stable compounds. Under standard conditions, XeF\(_6\) appears as a colorless, crystalline solid that reacts with moisture in the air. Its reactivity is due to the presence of six fluorine atoms, making it highly electronegative and prone to reacting with a variety of substances.
XeF\(_6\) is used in various chemical syntheses, primarily due to its ability to fluorinate compounds or act as a powerful oxidizing agent. Its structure is typically octahedral, which can distort depending on environmental factors such as temperature and the presence of other reactants.

• High oxidation state of xenon.
• Reacts readily due to fluorine content.
• Important in fluorination reactions and oxidative processes.

Silicon Dioxide

Silicon dioxide (SiO\(_2\)) is a widely recognized compound, commonly found in nature as quartz. This compound is characterized by its strong covalent bonds, giving it high stability and a unique hardness. SiO\(_2\) serves many roles in scientific processes due to its inert nature and widespread availability in the Earth's crust.
In chemical reactions, silicon dioxide acts mainly as a structural matrix or a source of silicon ions. When subjected to reactive conditions, like those involving fluorinating agents such as xenon hexafluoride, it can break down to form silicon tetrafluoride (SiF\(_4\)). This transformation indicates the complete substitution of oxygens by fluorines in the compound.

• Commonly found as quartz in nature.
• Involves strong covalent bonds.
• Transformed into SiF\(_4\) when reacted with fluorinating agents.

Product Formation

Product formation in chemical reactions often involves complex processes where reactants transform into one or more distinct products. In the specific case of xenon hexafluoride with silicon dioxide, the principal products are xenon oxytetrafluoride (XeOF\(_4\)) and silicon tetrafluoride (SiF\(_4\)). This follows a common theme of product formation with fluorinating agents where fluorine atoms act to replace other atoms or ions.
The formation of XeOF\(_4\) from XeF\(_6\) involves the substitution of one fluorine atom with an oxygen atom. Simultaneously, SiO\(_2\) loses its oxygen atoms to form SiF\(_4\), indicating a complete transformation. This dual transformation showcases the ability of fluorides to effectively displace atoms bonded through strong covalent interactions.

• Xenon oxytetrafluoride and silicon tetrafluoride are the products.
• Fluorinating process replaces oxygen with fluorine.
• Reflects the principle of atom substitution in product formation.

Reaction Mechanism

The reaction mechanism of xenon hexafluoride with silicon dioxide involves a sequence of steps leading to the formation of desired products. Firstly, XeF\(_6\) is exposed to SiO\(_2\), initiating a reaction where fluorine atoms start to interact with silicon and oxygen atoms from SiO\(_2\).
During this process, XeF\(_6\) undergoes partial hydrolysis which can incorporate oxygen into its structure, forming XeOF\(_4\). Concurrently, SiO\(_2\) converts into SiF\(_4\) as all oxygen atoms in SiO\(_2\) are replaced with the more electronegative fluorine atoms.

• Involves XeF\(_6\) reacting with SiO\(_2\).
• Partial hydrolysis may occur for XeF\(_6\).
• SiO\(_2\) transforms fully to SiF\(_4\) during the reaction.

Understanding the reaction mechanism helps visualize how the initial reactants rearrange to result in the products seen in such chemical interactions.