Problem 7 - 43 Years JEE ADVANCED (1978-2020) + JEE MAIN Chapterwise & Topicwise Solved Papers Chemistry

Question

Match the refining methods (Column I) with metals (Column II).. (I) Liquation (a) \(\mathrm{Zr}\) (II) Zone Refining (b) \(\mathrm{Ni}\) (III) Mond Process (c) Sn (IV) Van Arkel Method (d) Ga (a) (I) \(-(\mathrm{c}) ;(\mathrm{II})-(\mathrm{a}) ;(\mathrm{III})-(\mathrm{b}) ;(\mathrm{IV})-(\mathrm{d})\) (b) (I) - (b); (II) - (c); (III) - (d); (IV) - (a) (c) (I) \(-(\mathrm{c}) ;(\mathrm{II})-(\mathrm{d}) ;(\mathrm{III})-(\mathrm{b}) ;(\mathrm{IV})-(\mathrm{a})\) (d) (I) - (b); (II) - (d); (III) - (a)l (IV) - (c)

Step-by-Step Solution

Answer

Option (c) is the correct match.

Step 1: Understanding Liquation

Liquation is a refining process used for metals with low melting points, such as tin (Sn). This process helps separate a fusible metal from its impurities through partial melting.

Step 2: Understanding Zone Refining

Zone refining is used to obtain ultra-pure metals by heating a small region of a solid metal with an electric heater. This method is commonly used for semiconductor materials like silicon and gallium (Ga).

Step 3: Understanding Mond Process

The Mond Process is used to refine nickel (Ni). It involves converting nickel into nickel carbonyl, a volatile complex, and then decomposing it to pure nickel.

Step 4: Understanding Van Arkel Method

The Van Arkel Method is used to purify metals like zirconium (Zr) and titanium. It involves converting the metal into a volatile compound and then breaking it down to produce pure metal.

Step 5: Matching Refining Methods to Metals

Now we match the refining methods to the metals using our understanding: - Liquation (I) corresponds to Sn (c). - Zone Refining (II) corresponds to Ga (d). - Mond Process (III) corresponds to Ni (b). - Van Arkel Method (IV) corresponds to Zr (a).

Step 6: Identifying the Correct Option

Review the provided options and identify the one where the methods are matched correctly: - Option (c) (I)(c); (II)(d); (III)(b); (IV)(a) correctly matches each refining method to the respective metal.

Key Concepts

Refining Methods

In the world of metallurgy, refining methods are crucial for obtaining pure metals free of impurities. Refinement ensures that the metal can be used effectively in various applications. There are several methods employed, each suited for different types of metals and their specific properties. These techniques rely on the physical and chemical characteristics of the metal being processed.

Some common refining methods include:

• Liquation: used for metals with low melting points.
• Zone Refining: ideal for obtaining high-purity metals.
• Mond Process: tailored for refining nickel.
• Van Arkel Method: used for refining metals like zirconium and titanium.

Each method has its own specific chemical reactions and temperatures in which it operates best. The effectiveness of these refining methods ensures the usability and value of the metal extracted.

Liquation

Liquation is a specialized refining technique used for metals like tin (Sn) with low melting points. It involves partially melting the metal to separate it from impurities, which remain solid or can be removed easily from the molten metals. This process helps in achieving a higher purity level of the fusible metal.

During liquation:

• A fusible metal is melted while impurities are left behind.
• Gravity or a mechanical system can help in the separation process.
• Effective for separating compounds that have different melting points.

Liquation is quite efficient in scenarios where the main challenge is getting rid of contaminants from a metal that does not require very high precision purification. This method ensures that the metal can be utilized in applications that demand certain purity levels.

Zone Refining

The zone refining technique is essential for producing metals with ultra-high purity levels, making it particularly valuable in the semiconductor industry. This method uses a process where a narrow region of the metal is melted using an electric heater and slowly moved along the metal bar.

Zone refining works because:

• Impurities tend to migrate to the molten zone as the molten zone moves.
• The process can be repeated several times for higher purity.
• Commonly used for refining semiconductors like gallium (Ga) and silicon.

This technique capitalizes on the fact that impurities tend to concentrate in the liquid phase, allowing them to be moved away from the solidifying metal. It is ideal for materials requiring extremely low concentrations of impurities, which is crucial for manufacturing electronic components.

Mond Process

The Mond Process is a unique method designed for refining nickel (Ni) into a highly pure form. It features the conversion of nickel into a gaseous compound, nickel carbonyl \((Ni(CO)_4\), and then its decomposition back to pure metal.

Steps involved in the Mond Process include:

• Níckel is reacted with carbon monoxide at high pressure to form nickel carbonyl.
• The nickel carbonyl vapor then decomposes upon heating to yield pure nickel and carbon monoxide.
• Nickel produced is of very high purity.

This method is efficient and economical, especially because the nickel recovery process involves easily reversing the chemical reaction, making it suitable for industrial applications where a consistent supply of high-quality refined nickel is required.

Van Arkel Method

The Van Arkel Method is a fascinating and precise technique that purifies metals like zirconium (Zr) and titanium. This method is based on the conversion of metal contaminants into volatile compounds, which are then decomposed to obtain pure metal.

Key characteristics of the Van Arkel Method include:

• Conversion of the impure metal into a volatile iodide by reacting with iodine.
• Heating the volatile iodide decomposes it on a hot wire to produce high-purity metal.
• Known as the crystal bar process due to the formation of metal droplets or bars on the wire.

The Van Arkel Method is ideal when the utmost purity is crucial, especially for metals used as alloying ingredients in critical applications. Its precision allows for eliminating nearly all impurity traces, ensuring that the resulting metal meets high industry standards.

Transition Metals

Transition metals are a unique group of elements located in the center of the periodic table, specifically in groups 3 through 12. They are characterized by their ability to form stable compounds and exhibit variable oxidation states.

Unique characteristics of transition metals include:

• They often display high melting and boiling points.
• Known for their excellent conductivity of heat and electricity.
• Capable of forming complex compounds and alloys.
• Commonly have multiple oxidation states, making them versatile in chemical reactions.

Transition metals play a crucial role in various industries because of their strength, stability, and unique properties. They are frequently used in construction, electronics, and as catalysts in chemical processes, demonstrating their broad utility and importance in modern technology and industrial applications.