The correct option is (a).
Explanation
Coke is a carbonaceous material derived from the destructive distillation of coal. It is considered an almost pure form of carbon and plays a critical role in industrial metallurgy due to its chemical properties as a reducing agent.
Statement-wise Analysis
- Statement 1 is Correct: Coke is physically characterized as a tough, porous, and black substance. It is produced by heating coal in the absence of air, which removes volatile impurities, leaving behind a carbon-rich residue.
- Statement 2 is Incorrect: Coke is primarily used in the manufacture of steel and industrial metallurgy. It is not primarily used in the manufacture of plastic; plastics are generally derived from petrochemicals (fractions of petroleum and natural gas).
- Statement 3 is Incorrect: Coke is extensively used in the extraction of metals (such as iron, copper, and zinc) from their ores. It acts as a reducing agent to remove oxygen from metal oxides. Limiting its use to the extraction of non-metals like sulphur only is factually wrong.
Key Takeaway
Coke is a tough, porous, and pure form of carbon used primarily as a fuel and a reducing agent in the manufacture of steel and the extraction of metals.