Tag: extraction of metals from ore

Quizzes (0) Questions (78)

Questions Related to extraction of metals from ore

Multiple choice chemistry production of metals extraction of metal from concentrated ore basics of metallurgy extraction of metals from ore

The order of processes involved in the dressing of an ore are :
(i) grinding and crushing           (ii) hand picking                (iii) pulverization

  1. (i), (ii), (iii)

  2. (i), (iii), (ii)

  3. (ii), (iii), (i)

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

Dressing of ore can be carried out by first handpicking followed by crushing and grinding and then pulverization.


Hence, the correct option is $(D)$

Multiple choice chemistry production of metals extraction of metal from concentrated ore basics of metallurgy extraction of metals from ore

The process of carrying out the reduction of metal oxides by heating with coke is termed as :

  1. Roasting

  2. Smelting

  3. Zone refining

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

Smelting is the process where heat is applied to ore to extract the base metal, using a reducing agent. So, it is used to carry out reduction of metal oxides to metal by heating with coke.

Multiple choice chemistry production of metals extraction of metal from concentrated ore basics of metallurgy extraction of metals from ore

The above process is:

$HgS\xrightarrow{O _2}HgS.HgO$
                         $\downarrow\Delta$
                        $Hg$ 

  1. auto oxidation

  2. self reduction

  3. thermal reduction

  4. none of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Cinnabar ($HgS$), when heated with a current of $O _2$ gets reduced to $Hg$ without the need of any additional reducing agent. The process involved is known as self reduction

Multiple choice chemistry production of metals extraction of metal from concentrated ore basics of metallurgy extraction of metals from ore

In which of the following chemical leaching is used either in the extraction of metal or in the concentration of ore?

  1. Argentite

  2. Bauxite

  3. Alluvial sand containing gold

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

Chemical leaching is used in the extraction of silver from Argentite (Ag2S) using sodium cyanide solution.

Multiple choice chemistry production of metals extraction of metal from concentrated ore basics of metallurgy extraction of metals from ore

Which one of the following statements is incorrect about rock salt type?

  1. It has fcc arrangement of $\mathrm { Na } ^ { + }$
  2. Nat and Cl-ions have a co-ordination number of $6:6$
  3. A unit cell of $NaCl$ consists of four $NaCl$ units

  4. All halides of alkali metals have rock-salt type structure
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The alkali halides crystallize in the NaCl structure also known as rock-salt structure (rock salt is the mineral form of sodium chloride); exceptions being CsCl, CsBr, and CsI, which crystallize in the CsCl structure. In the NaCl structure (face-centered cubic lattice), each cation is surrounding by six anions, and vice versa (coordination number of 6). In the CsCl structure, each cation is surrounded by eight anions and vice versa (coordination number of 8).

Option D is incorrect

Multiple choice chemistry production of metals extraction of metal from concentrated ore basics of metallurgy extraction of metals from ore

The extraction of metals from oxide ores may involve:

  1. reduction with carbon

  2. reduction with aluminium

  3. electrolyte reduction

  4. reduction with CO
Reveal answer Fill a bubble to check yourself
A,B,C,D Correct answer
Explanation

These are the methods for extraction of metals from oxide ores:
Carbon reduction, involving reduction with CO or C
Self reduction
Thermite reduction, which employs Al
Electrolytic reduction.

Multiple choice chemistry production of metals extraction of metal from concentrated ore basics of metallurgy extraction of metals from ore

The advantage(s) of using carbon to reduced a number of oxides and other compounds are :

  1. easy availability of coke.

  2. low cost of carbon.

  3. tendency of carbon to show catenation..

  4. presence of carbon lowers the melting point of the oxide.
Reveal answer Fill a bubble to check yourself
A,B Correct answer
Explanation

The advantage(s) of using carbon to reduced a number of oxides and other compounds are
 (i) easy availability of coke.
 (ii) low cost of carbon.
 (iii) exothermic nature of reaction which requires less energy to keep the furnace hot.


Hence, A and B are the correct options. 

Multiple choice chemistry production of metals extraction of metal from concentrated ore basics of metallurgy extraction of metals from ore

The extraction of metals from oxide ores involve :

  1. reduction with carbon

  2. reduction with aluminium

  3. electrolyte reduction
  4. reduction with $CO$
Reveal answer Fill a bubble to check yourself
A,B,C,D Correct answer
Explanation

During extraction of metals from oxide ores, the reduction of metal ore to crude metal can be carried out by using several methods such as pyrometallurgy, hydrometallurgy and electrometallurgy. Various reducing agents such as carbon, hydrogen, aluminum or other metals can be used. CO also reduces metal ores to crude metals.