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Multiple choice chemistry separation of matter sedimentation, decantation and filtration other methods of separation separation methods

Put the following 6 steps for separating sand and salt into the correct order:

A.  Heat filtrate to evaporate off the solvent (water).

B.  Pour salt water filtrate into an evaporating basin on a tripod over a Bunsen burner.

C.  Filter to remove the insoluble sand.

D.  Place the sand/salt mixture into a beaker and add water.

E.  Allow basin to cool & collect salt.

F.  Stir to allow the salt to dissolve in the water.

  1. $CDFBAE$
  2. $CDBAFE$
  3. $DFCBAE$
  4. $ABCDEF$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The correct order of the process would be DFCBAE as shown below.

D.  Place the sand/salt mixture into a beaker and  add water

F.  Stir to allow the salt to dissolve in the water

C.  Filter to remove the insoluble sand

B.  Pour salt water filtrate into an evaporating basin on a tripod over a Bunsen burner

A.  Heat filtrate to evaporate off the solvent (water)

E.  Allow basin to cool & collect salt

Multiple choice chemistry separation of matter sedimentation, decantation and filtration other methods of separation separation methods

Which of the following is a seperation technique to seperate potassium chloride and ammonium chloride?

  1. Distillation

  2. Evaporation

  3. Condensation

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

A mixture of ammonium chloride and potassium chloride can be separated using the process of sublimation. You must also note that both these substances are sublimable. This technique is quite feasible in this case as the sublimable temperatures of ammonium and potassium chloride differ widely. Between the two, ammonium chloride has lower sublimable temperature. Therefore, it sublimes first followed by potassium chloride.

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

Which of the following is not a method of refining of metals?

  1. Electrolysis

  2. Smelting

  3. Poling

  4. Liquation
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Smelting is process in which metal is extracted from its ore by heating and melting. It is not a method of refining metal. Methods of refining metals are electrolysis poling, liquation, zone refining, vapour phase refining, distillation.

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

Which one of the following is the true in electrolytic refining?

  1. Impure metal is made cathode.

  2. Impure metals is made anode.

  3. Impure metals is made cathode and pure metal as anode.

  4. Both electrodes must be of pure metal.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
  • In Electrolytic refining, the impure metal is made to act as an anode. A strip of the same metal in pure form is used as a cathode. 
  • They are put in a suitable electrolytic bath containing a soluble salt of the same metal. 
  • The more basic metal remains in the solution and the less basic ones go to the anode mud.
  • Zinc, copper is refined by this method.
Multiple choice chemistry production of metals refining of metals basics of metallurgy basic metallurgical processes

Four metals and their methods of refinement are given
(i) $Ni,\ Cu,\ Zr,\  Ga$
(ii) Electrolysis, van Arkel process, zone refining, Mond's process
Choose the right method for each:

  1. $Ni:$ Electrolysis, $Cu:$ van Arkel process, $Zr:$ Zone refining, $Ga:$ Mond's process
  2. $Ni:$ Mond's process, $Cu:$ Electrolysis, $Zn:$ van Arkel process, $Ga:$ Zone refining
  3. $Ni:$ Mond's process, $Cu:$ van Arkel process, $Zr:$ Zone refining, $Ga:$ Electrolysis
  4. $Ni:$ Electrolysis, $Cu:$ Zone refining, $Zr:$ van Arkel process, $Ga:$ Mond's process
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

$Ni$ is refined by Mond's process.

$Cu$ is refined by Electrolysis.
$Zn$ is refined by Van Arkel process.
$Ga$ is refined by Zone refining.

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

Mark the correct statements:

(i) mercury can be refined by the process of distillation.

(ii) In poling, the molten impure metal is stirred with green poles of wood.

(iii) In electrolyte refining of metals, impure metal is made as cathode and a thin strip of pure metal is made as anode.

  1. (i) and (ii)

  2. (i) and (iii)

  3. (ii) and (iii)

  4. (i), (ii) and (iii)
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Low boiling point metals like Mercury are purified with distillation.

Hence,  statement (i) is correct.
 
The heat of  copper makes the pole emit wood gas that reduces the cuprous oxide to copper.
In poling, the molten impure metal is stirred with green poles of wood.
Hence,option (ii) is correct.

In electrolyte refining of metals, impure metal is made as Anode  and a thin strip of pure metal is made as cathode.
Hence, option (iii) is incorrect.

Multiple choice chemistry metals and non metals refining of metals basics of metallurgy basic metallurgical processes

Electrolysis is used for refining certain metals such as copper and zinc.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Electrolysis, process by which electric current is passed through a substance to effect a chemical change. The chemical change is one in which the substance loses or gains an electron (oxidation or reduction).

It is extensively used in metallurgical processes, such as in extraction (electrowinning) or purification (electrorefining) of metals from ores or compounds and in deposition of metals from solution (electroplating). Electrolysis of salt of copper and zinc results in the deposition of pure copper and zinc on cathode of the electrolytic cell.
option A is correct

Multiple choice chemistry metals and non metals refining of metals basics of metallurgy basic metallurgical processes

In the electrolytic refining of a metal M, what would you take as the anode is : 

  1. impure metal M

  2. thin strip of pure metal M

  3. solution of salt of the metal M

  4. none of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The purest copper is obtained by an electrolytic process using impure copper as the anode and a thin sheet of pure copper as cathode. The electrolyte is an acidic solution of copper sulphate. By passing electricity copper is dissolved from anode and deposits at cathode.