1. Which of the following is an ore of iron?
Answer:
Explanation:
Hematite (Fe2O3) is an iron ore, while the other options are ores of different metals.
2. The process in which ore is heated in the absence of air is known as:
Answer:
Explanation:
Calcination is the process of heating an ore in the absence of air to drive away moisture and volatile impurities.
3. Which method is used for refining of noble metals like gold and silver?
Answer:
Explanation:
Noble metals such as gold and silver are refined using the electrolytic refining method.
4. Froth flotation is used for the concentration of:
Answer:
Explanation:
The froth flotation process is mainly used for the concentration of sulphide ores.
5. Which of the following ores is best concentrated by leaching?
Answer:
Explanation:
Bauxite, an ore of aluminum, is best concentrated by the leaching process using sodium hydroxide.
6. The process used for the extraction of metals in the middle of the activity series, such as iron, is:
Answer:
Explanation:
Metals in the middle of the activity series like iron are extracted by reduction with carbon.
7. Which of the following metals is obtained by the electrolysis of its molten chloride?
Answer:
Explanation:
Sodium is obtained by the electrolysis of its molten chloride (NaCl).
8. The role of silica in the metallurgy of copper is to:
Answer:
Explanation:
In the metallurgy of copper, silica acts as a flux and combines with acidic impurities to form a slag.
9. Which of the following is a flux in the extraction of iron from hematite?
Answer:
Explanation:
Limestone (CaCO3) acts as a flux in the extraction of iron from hematite.
10. The method used for refining zinc is:
Answer:
Explanation:
Zinc is refined using distillation as it has a low boiling point.
11. In the extraction of chlorine by electrolysis of brine, which of the following gases is released at the anode?
Answer:
Explanation:
In the electrolysis of brine, chlorine is released at the anode.
12. Which process involves the use of bacteria to extract gold from gold-bearing minerals?
Answer:
Explanation:
Bioleaching involves the use of bacteria to extract gold from gold-bearing minerals.
13. Which of the following elements is refined by the Mond process?
Answer:
Explanation:
Nickel is refined using the Mond process which involves the conversion of nickel to its volatile carbonyl complex.
14. The metal which can be extracted by the cyanide process is:
Answer:
Explanation:
The cyanide process is used for the extraction of silver.
15. An amalgam is an alloy of:
Answer:
Explanation:
An amalgam is an alloy of either gold or silver with mercury.
16. The chief ore of aluminum is:
Answer:
Explanation:
Bauxite is the chief ore of aluminum.
17. The primary purpose of flux in metallurgical processes is to:
Answer:
Explanation:
Flux helps in converting the impurities into slag which can be easily removed.
18. Which metal is extracted by the Hall-Heroult process?
Answer:
Explanation:
Aluminum is extracted by the Hall-Heroult process from purified alumina.
19. Which of the following processes is not a chemical refining process?
Answer:
Explanation:
Zone refining is a physical method used to purify metals based on the principle of the difference in solubility.
20. Calcination of an ore is done to:
Answer:
Explanation:
Calcination is carried out to remove moisture and volatile impurities by heating the ore below its melting point.