Tag: basics of metallurgy

Questions Related to basics of metallurgy

During extraction of metals, electrolytic refining is used to obtain pure metals. Material which will be used as anode, for refining of silver metal by this process, is:

  1. zinc

  2. impure silver

  3. pure silver

  4. iron


Correct Option: B
Explanation:

Electrolysis is the dissolving of metal from one electrode of an electrolytic cell to another electrode in pure form. It gives the highest purity metal product. The impure silver is cast into a slab which is the anode, while pure silver sheet metal is the cathode.

Sodium is obtained by the electrolysis of:

  1. an aqueous solution of sodium chloride

  2. an aqueous solution of sodium hydroxide

  3. fused sodium chloride

  4. fused sodium sulphate


Correct Option: C
Explanation:

Sodium is obtained by the electrolysis of fused mixture of $NaCl$ and $CaCl _2$ (Down's process). Reaction can be written as:

$2NaCl \rightarrow 2Na + {Cl} _2$


last process of metallurgy is ?

  1. Refining

  2. Concentration

  3. Reduction

  4. Smelting


Correct Option: A
Explanation:

After extraction and separation, refining is the last process of Metallurgy. It involves the refining of pure metal finally. 

Which of the following pair can be refined using same basic principle?

  1. $Cu$ and $Ag$

  2. $Si$ and $Ge$

  3. $Ti$ and $Ni$

  4. All of these


Correct Option: A

In the refining of copper, pure copper is deposited on:

  1. Anode

  2. Cathode

  3. 1 and 2 both

  4. None of these


Correct Option: B
Explanation:

In electrorefining step, impurities like Fe, Ni, Zn get dissolved in the solution while Au, Ag and Pt are deposited as anode mud below the anode and pure copper deposited at cathode.

Zirconium is purified by 

  1. Liquidation

  2. Electrolytic process

  3. Van Arkel method

  4. Calcination


Correct Option: C

(a) Mond process       (1) Ni
(b) Van-Arkel              (2) Zr
(c) Liquation               (3) Ga
(d)Zone refining         (4) Sn
Correct option is:

  1. $a-(1)$ $ b-(2)$ $c-(2)$ $d-(4)$

  2. $a-(1)$ $b-(2) $ $c-(4)$ $d-(3)$

  3. $a-(3)$ $b-(2)$ $c-(4)$ $d-(1)$

  4. $a-(2)$ $b-(3)$ $c-(4)$ $d-(1)$


Correct Option: B
Explanation:
Solution:- (B) $a-(1)$ $b-(2) $ $c-(4)$ $d-(3)$
(a) Mond process     $ \Rightarrow$ Ni
(b) Van-Arkel            $ \Rightarrow$ Zr
(c) Liquation             $ \Rightarrow$ Sn
(d)Zone refining       $ \Rightarrow$ Ga

An insoluble substance or mixture that collects at the anode in an electrolytic refining or plating process is known as anode mud.

State True or False.

  1. True

  2. False

  3. Cannot be determined

  4. None of the above


Correct Option: A
Explanation:

Anode mud is the insoluble impurity which settles down at the bottom of the anode during electrolytic refining. The soluble impurities go into the solution.

So the given statement is correct
Hence option $A$ is correct.

Gold is extracted by hydrometallurgical process, based on its property:

  1. of being electropositive

  2. of being less reactive

  3. to form complex which are water soluble

  4. to form salt which are water soluble


Correct Option: C
Explanation:
Hydrometallurgy is a method for obtaining metals from their ores. It is a technique within the field of extractive metallurgy involving the use of aqueous chemistry for the recovery of metals from ores, concentrates, and recycled or residual materials. Gold is extracted by hydrometallurgical process, based on its property to form complexes which are water soluble.

$4Au(s)+8CN^- +O _2(g)+2H _2O\rightarrow \underset{soluble \, complex}{4[Au(CN) _2]^-} + 4OH^-$

Which of the following is true for electrolytic refining?

  1. Pure metal is anode and impure metal is cathode

  2. Pure metal is cathode and impure metal is anode

  3. Both are anode

  4. Both are cathode


Correct Option: B
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.