Tag: chemistry

Quizzes (490) Questions (9892)

Questions Related to chemistry

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

Match the following.

Separation process Purpose for which we do the separation What do we do with the separated components
1) Separate stones from rice a) To remove non useful components i) We throw away the impurities
2) Churning milk to obtain butter b) To remove impurities or harmful components ii) we throw away the solid component
3) Separate tea leaves c) to separate two different but useful components. iii) we use both the components.


  1. 1) c) ii)

    2) a) i)

    3) b) iii)

  2. 1) c) ii)

    2) b) i)

    3) a) iii)

  3. 1) c) ii)

    2) a) iii)

    3) b) i)

  4. 1) a) ii)

    2) c) i)

    3) b) iii)
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Separation process Purpose for which we do the separation What do we do with the separated components
1) Separate stones from rice c) to separate two different but useful components. ii) we throw away the solid component
2) Churning milk to obtain butter a) To remove non useful components i) We throw away the impurities
3) Separate tea leaves b) To remove impurities or harmful components iii) we use both the components.


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

Which of the following represents correct statement(s)?

  1. The method of handpicking can be used for separating slightly larger sized impurities like the pieces of dirt, stone and husk from wheat, rice or pulses.

  2. The quantity of such impurities is usually very large.

  3. In such situations, we find that handpicking is not a convenient method of separating substances.

  4. All of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The statement (A) represents correct statement.
The method of handpicking can be used for separating slightly larger sized impurities like the pieces of dirt, stone and husk from wheat, rice or pulses.
The quantity of such impurities is usually not very large.
In such situations, we find that handpicking is a convenient method of separating substances.

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

Which of the following represents incorrect statement(s)?

  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
Reveal answer Fill a bubble to check yourself
D Correct answer
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.

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

Which of the following represents correct statement(s)?

  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.
Reveal answer Fill a bubble to check yourself
D Correct answer
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.

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

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

  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
Reveal answer Fill a bubble to check yourself
B Correct answer
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.
 $\displaystyle Ni+4CO \xrightarrow {\text {330-350 K}} Ni(CO) _4$
 $\displaystyle Ni(CO) _4 \xrightarrow { \text {450-470 K}}  \underset {\text {Pure metal }}{Ni}+ 4 CO$

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

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

  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.
Reveal answer Fill a bubble to check yourself
A,D Correct answer
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.

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

Silver can be separated from lead by:

  1. Distillation

  2. Amalgamation

  3. Filtration

  4. Cupellation
Reveal answer Fill a bubble to check yourself
D Correct answer
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.