Q1: Catalyst used in the 'catalytic converter' employed in automobile exhaust line for complete combustion/oxidation of carbon monoxide, nitrogen oxides and hydrocarbons is

ANS:B - platinum

Platinum is a rare and precious metal known for its remarkable properties and various applications. Here are some key points about platinum:

1. Chemical Properties: Platinum is a dense, malleable, and ductile metal with a silvery-white color. It is highly resistant to corrosion and tarnishing, making it suitable for various industrial and jewelry applications.
2. Catalytic Properties: Platinum exhibits excellent catalytic activity, especially at high temperatures. It is widely used as a catalyst in the automotive industry, particularly in catalytic converters, where it helps convert harmful pollutants in vehicle exhaust gases into less harmful substances.
3. Industrial Applications: Apart from catalytic converters, platinum is used in various industrial processes, including petroleum refining, chemical manufacturing, and the production of electronic components. It is also used in laboratory equipment, thermocouples, and glassmaking.
4. Jewelry: Platinum is highly valued in jewelry making due to its rarity, durability, and hypoallergenic properties. It is often alloyed with other metals such as iridium, ruthenium, or palladium to improve its hardness and workability.
5. Investment: Platinum is considered a precious metal along with gold, silver, and palladium. It is traded on commodity markets and is used as a store of value and a hedge against inflation.
6. Medical Applications: Platinum-based drugs, such as cisplatin and carboplatin, are used in chemotherapy to treat various types of cancer. These drugs work by interfering with the replication of cancer cells.

Overall, platinum is a versatile and valuable metal with diverse applications across industries, ranging from automotive and chemical to jewelry and medicine. Its unique combination of properties makes it indispensable in many technological and medical advancements.