Extraction of Metals

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What is the purpose of adding freshly precipitated aluminium hydroxide to the filtrate?

To remove impurities from the filtrate (correct)

To reduce the pH of the filtrate

To increase the concentration of the filtrate

To facilitate the precipitation of aluminium hydroxide

Which process involves the reaction between an oxide and aluminium powder to produce a metal?

Electrolytic reduction process

Hydrometallurgical process

Aluminothermic process (correct)

Self-reduction process

What is the purpose of smelting in the extraction of metals?

To reduce the metal oxide to its elemental form

To separate the metal from its ore (correct)

To convert the ore into a more reactive form

To purify the metal

What is the distinguishing feature of the self-reduction process?

It does not require an external reducing agent Signup and view all the answers

Which process is used to extract metals such as chromium and manganese on a commercial scale?

Aluminothermic process Signup and view all the answers

What is the primary purpose of the electrolytic refining process?

To remove impurities from the metal by deposition on the cathode Signup and view all the answers

Which of the following statements is TRUE about the reverberatory furnace?

The fuel burns in a separate part and does not mix with the charge Signup and view all the answers

What is the reaction at the anode during the extraction of sodium?

Cl⁻ → Cl + e⁻ Signup and view all the answers

What is the primary difference between calcination and roasting?

Calcination is used to convert metal oxides into metals, while roasting is used to convert metal sulfides into oxides Signup and view all the answers

What is the process of extracting metals like gold and silver from their native ores?

Amalgamation process Signup and view all the answers

What is the primary purpose of leaching in metallurgy?

To extract metals from their ores by dissolving the ore in a solvent Signup and view all the answers

What is the primary difference between smelting and refining?

Smelting is used to extract metals from their ores, while refining is used to purify metals Signup and view all the answers

What is the reaction of tin oxide with carbon?

SnO₂ + 2C → Sn + 2CO Signup and view all the answers

What is the purpose of refining metals?

To purify impure metals Signup and view all the answers

What is the method of extraction used for metals like cadmium, copper, and silver?

Precipitation or metal displacement method Signup and view all the answers

What is the primary purpose of cupellation?

To purify silver by removing lead impurities Signup and view all the answers

What is the final product obtained through Mond's process?

Pure nickel Signup and view all the answers

Which of the following metals are refined using the Van Arkel process?

Ti, Zr, Hf Signup and view all the answers

What is the principle behind zone refining or fractional crystallisation?

Difference in solubility of impurities in molten and solid state of metals Signup and view all the answers

What is the result of heating impure silver in a blast of air using cupellation?

Oxidation and removal of lead impurities Signup and view all the answers

Which method of refining involves the decomposition of a compound into a pure metal?

Thermal dissociation Signup and view all the answers

What is the primary method of refining easily fusible metals like lead and tin?

Liquation Signup and view all the answers

Which of the following metals can be purified by distillation?

Zinc and Mercury Signup and view all the answers

What is the purpose of fractional distillation in the metallurgy of zinc?

Separating cadmium from zinc Signup and view all the answers

Which of the following methods of refining involves the formation of a compound, which is then decomposed into a pure metal?

Thermal dissociation Signup and view all the answers

What is the primary purpose of concentration or dressing of the ore?

To separate the large bulk of impurities from the ore Signup and view all the answers

Which type of ores are very few in nature?

Metallic halides Signup and view all the answers

What is the name of the process that separates ore particles based on the difference in specific gravity?

Gravity Separation or levigation Signup and view all the answers

What is the name of the table used in the gravity separation process?

Wilfley table Signup and view all the answers

What is the term used to describe the large amount of unwanted impurities in the ore?

Gangue or matrix Signup and view all the answers