Match Column I with Column II

A-s; B-r; C-q; D-p

The correct answer is option 2. A-s; B-r; C-q; D-p.

Let us delve deeper into each process and its corresponding material:

A. Zone refining: s. Germanium:

Zone refining is a highly effective method for purifying semiconductors, including germanium and silicon. The process relies on the principle that impurities tend to concentrate more in the liquid phase than in the solid phase of a material.

Here is how the process typically works:

1. A rod of the impure semiconductor, such as germanium, is clamped horizontally and heated at one end to melt it.

2. A narrow molten zone is then passed along the length of the rod, usually in the opposite direction of the heat source.

3. As the molten zone moves, impurities tend to segregate preferentially into the molten portion, leaving behind a more purified solid phase.

4. This purified portion is then gradually moved along the rod, and the process is repeated until the desired level of purity is achieved.

Zone refining is particularly effective for removing trace impurities, resulting in very high-purity materials. Germanium, being a crucial semiconductor material used in electronics, benefits greatly from this purification method.

B. Mond's process: r. Nickel:

Mond's process is a technique used for refining nickel to high purity levels. This process is based on the formation and subsequent decomposition of nickel carbonyl, a volatile compound of nickel.

Here is a simplified overview of the process:

1. Nickel is reacted with carbon monoxide at high temperatures to form nickel carbonyl gas (Ni(CO)₄).

2. The nickel carbonyl is then subjected to lower temperatures, causing it to decompose, yielding pure nickel metal and carbon monoxide gas.

3. The pure nickel can then be collected and further processed as needed.

Mond's process is particularly useful for refining nickel ores that may contain various impurities. It allows for the production of high-purity nickel suitable for various industrial applications, including stainless steel production and electronic components.

C. Liquation: q. Lead:

Liquation is a separation process used to purify metals with different melting points, such as lead and tin. This method exploits the fact that metals and their impurities often have different melting points, allowing for selective separation.

For lead purification:

1. The impure lead is heated to a temperature just below its melting point.

2. As the temperature rises, the lead begins to melt, while the higher-melting impurities remain solid.

3. The molten lead, enriched in purity, is then collected separately from the solid impurities.

Liquation is particularly effective for removing impurities that have significantly higher melting points than the metal being purified. It's commonly used in the refining of lead and tin, where impurities such as copper, arsenic, and antimony are left behind as solid residues.

D. van-Arkel: p. Titanium:

The van-Arkel process is a chemical method used to produce high-purity titanium metal from its tetrachloride compound. This process is based on the reaction between titanium tetrachloride (TiCl₄) and a more reactive metal, typically magnesium or sodium.

Here is how the van-Arkel process typically works:

1. Titanium tetrachloride is reacted with liquid magnesium or sodium at elevated temperatures.

2. The reaction forms solid titanium sponge and magnesium or sodium chloride as a byproduct.

3. The titanium sponge is then collected and further processed to obtain the desired form of titanium metal.

The van-Arkel process is crucial for producing titanium of high purity, suitable for various applications in aerospace, medical implants, and chemical industries.

Each of these processes plays a vital role in refining and purifying specific metals for various industrial applications.