Question 21:
Which process is primarily used to recover gold from its ores?
A) Hydrometallurgy
B) Pyrometallurgy
C) Amalgamation
D) Leaching
Answer: D) Leaching
Explanation: Leaching, especially with cyanide, is a common method for recovering gold from its ores, where gold is dissolved and then extracted from the solution.
Question 22:
What is the primary purpose of using carbon in the reduction of metal oxides?
A) To oxidize the metal
B) To act as a flux
C) To provide energy
D) To reduce the metal oxide to metal
Answer: D) To reduce the metal oxide to metal
Explanation: Carbon acts as a reducing agent, providing electrons to reduce metal oxides into their elemental form during smelting processes.
Question 23:
Which of the following methods is used to concentrate copper ore?
A) Flotation
B) Amalgamation
C) Electrolysis
D) Distillation
Answer: A) Flotation
Explanation: The flotation process separates minerals based on differences in their hydrophobic properties, making it effective for concentrating copper ores.
Question 24:
What is the role of a flux in the smelting process?
A) To increase the temperature of the furnace
B) To help separate metal from impurities
C) To provide oxygen for combustion
D) To cool the molten metal
Answer: B) To help separate metal from impurities
Explanation: Flux is added to the smelting process to combine with impurities, forming slag that can be easily removed, allowing for purer metal extraction.
Question 25:
Which of the following metals is primarily extracted using the electrolysis method from its ore?
A) Gold
B) Silver
C) Aluminum
D) Lead
Answer: C) Aluminum
Explanation: Aluminum is extracted from its ore (bauxite) using electrolytic reduction, where aluminum oxide is dissolved and reduced to aluminum metal.
Question 26:
In metallurgy, what is “pyrometallurgy”?
A) Extraction of metals using aqueous solutions
B) Extraction of metals using heat
C) Extraction of metals using microbes
D) Extraction of metals at room temperature
Answer: B) Extraction of metals using heat
Explanation: Pyrometallurgy refers to the process of extracting metals from their ores using high temperatures, typically involving smelting or roasting.
Question 27:
What is the main disadvantage of the use of cyanide in gold extraction?
A) It is too expensive
B) It is highly toxic
C) It does not dissolve gold
D) It requires high temperatures
Answer: B) It is highly toxic
Explanation: Cyanide is highly toxic to humans and the environment, posing significant risks during its use in gold extraction processes.
Question 28:
Which of the following is NOT a method of separating metal from ore?
A) Filtration
B) Roasting
C) Distillation
D) Sintering
Answer: A) Filtration
Explanation: Filtration is generally not a method used for separating metals from ores. Roasting, distillation, and sintering are metallurgical processes used for separation and extraction.
Question 29:
Which type of furnace is used for the extraction of iron from iron ore?
A) Cupola furnace
B) Electric arc furnace
C) Blast furnace
D) Reverberatory furnace
Answer: C) Blast furnace
Explanation: The blast furnace is specifically designed for the extraction of iron from iron ore through a continuous process of smelting with coke and limestone.
Question 30:
What is the primary component of cast iron?
A) Nickel
B) Manganese
C) Carbon
D) Chromium
Answer: C) Carbon
Explanation: Cast iron primarily consists of iron with a carbon content of more than 2%, which contributes to its castability and strength.
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