Tag: refining of metals

Questions Related to refining of metals

Which of the following represents incorrect statement(s)?

chemistry production of metals refining of metals basics of metallurgy basic metallurgical processes

  1. The process that is used to separate grain from stalks is winnowing.

  2. In this process, the grain seeds are beaten to free the stalks.

  3. Threshing is not done with the help of bullocks. Machines are used to thresh even small quantities of grains.

  4. All of the above

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Correct Option: D
Explanation:

All of the given options represents incorrect statements.
The process that is used to separate grain from stalks is threshing. In this process, the stalks are beaten to free the grain seeds.
Threshing is done with the help of bullocks. Machines are also used to thresh large quantities of grains.

Which of the following represents correct statement(s)?

chemistry production of metals refining of metals basics of metallurgy basic metallurgical processes

  1. Ginning was traditionally done by machines.

  2. These days, ginning is also done by hand.

  3. Both of the above.

  4. None of the above.

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Correct Option: D
Explanation:

Ginning was traditionally done by hand. These days, machines are also used for ginning.
Note:The ginning of cotton is the process of separation of fibres from the seeds by combing.
From the bolls, cotton is usually picked by hand. Fibres are then separated from the seeds by combing. This process is called ginning of cotton.

Sieves are used at construction sites to separate pebbles and stones from sand.

chemistry production of metals refining of metals basics of metallurgy basic metallurgical processes

  1. True

  2. False

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Correct Option: A
Explanation:

Sieves are used at construction sites to separate pebbles and stones from sand. Sieves are also used to separate fine flour particles from the bigger impurities.

Nickel metal is purified by the vapour phase refining process. This process is based on the fact that:

chemistry production of metals refining of metals basics of metallurgy basic metallurgical processes

  1. nickel metal sublimes at high temperature

  2. nickel reacts with carbon monoxide to form nickel carbonyl which decomposes at high temperature to form nickel

  3. nickel reacts with chlorine to form nickel chloride which is volatile and decomposes easily to nickel

  4. nickel can be vapourized under vacuum leaving behind impurities

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Correct Option: B
Explanation:

Nickel metal is purified by the vapour phase refining process. This process is based on the fact that nickel reacts with carbon monoxide to form highly volatile nickel tetracarbonyl which decomposes at high temperature to form pure nickel metal.
 $\displaystyle Ni+4CO \xrightarrow {\text {330-350 K}} Ni(CO) _4$
 $\displaystyle Ni(CO) _4 \xrightarrow { \text {450-470 K}}  \underset {\text {Pure metal }}{Ni}+ 4 CO$

Group II. A elements are extracted from their chlorides by..........reduction.

chemistry production of metals refining of metals basics of metallurgy basic metallurgical processes

  1. Magnetic

  2. Static

  3. Electrolytic

  4. Dymanic

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Correct Option: C
Explanation:

Because of their electronegativity of the chlorine atom in their ores, the electronic influence is more. So, they are extracted by electrolytic reduction. 

Which of the following statements is/are correct regarding metallurgy?

chemistry production of metals refining of metals basics of metallurgy basic metallurgical processes

  1. Both calcination and roasting are generally carried out in the same furnace, i.e., reverberatory furnace.

  2. The slag formed during the extraction of Copper metal from Chalcopyrites ore is $CaSiO _3$.

  3. Mond's process involved in the extraction of nickel is related with formation and decomposition of a square planner complex of nickel metal.

  4. In case of electrolytic refining of extracted metals, generally impure metal rod is made the anode and pure metal rod is made the cathode.

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Correct Option: A,D
Explanation:

Both calcination and roasting are generally carried out in the this furnace, one in absence of air and other in presence of air.
The slag formed during the extraction of Copper metal from Chalcopyrites ore is $FeSiO _3$.
Mond's process involved in the extraction of Nickel is related with formation and decomposition of a tetrahedral complex of nickel metal $[Ni(CO) _4]$. 

In case of electrolytic refining of extracted metals, generally impure metal rod is made the anode and pure metal rod is made the cathode. This is evident as at anode, we get impure slag and at cathode, we get pure metal.

Silver can be separated from lead by:

chemistry principles and processes of isolation of elements refining of metals basics of metallurgy basic metallurgical processes

  1. Distillation

  2. Amalgamation

  3. Filtration

  4. Cupellation

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Correct Option: D
Explanation:

Cupellation is a process where ores are treated under high temperatures and controlled operations to separate noble metals like gold and silver from base metals like lead, copper, zinc, and others present in the ore or alloyed metal.

Refining of silver is done by___________.

chemistry principles and processes of isolation of elements refining of metals basics of metallurgy basic metallurgical processes

  1. liquidation

  2. poling

  3. cupellation

  4. van Arkel method

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Correct Option: C
Explanation:

Cupellation is a process where ores are treated under high temperatures and controlled operations to separate noble metals like gold and silver, from base metals like led, copper, zinc, and others present in the ore or alloyed metal.

Refining of silver is done by________.

chemistry principles and processes of isolation of elements refining of metals basics of metallurgy basic metallurgical processes

  1. liquidation

  2. Poling

  3. cupellation

  4. van Aekel method

Show answer
Correct Option: C
Explanation:

Cupellation is a process where ores are treated under high temperatures and controlled operations to separate noble metals like gold and silver, from base metals like led, copper, zinc, and others present in the ore or alloyed metal.

Cupellation process is used in the metallurgy of:

chemistry principles and processes of isolation of elements refining of metals basics of metallurgy basic metallurgical processes

  1. Copper

  2. Silver

  3. Aluminium

  4. Iron

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Correct Option: B
Explanation:

Cupellation is a process where ores are treated under high temperatures and controlled operations to separate noble metals like gold and silver, from base metals like led, copper, zinc, and others present in the ore or alloyed metal.