Tag: production of metals

Questions Related to production of metals

Sodium is obtained by the electrolysis of:

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

  1. an aqueous solution of sodium chloride

  2. an aqueous solution of sodium hydroxide

  3. fused sodium chloride

  4. fused sodium sulphate

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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 ?

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

  1. Refining

  2. Concentration

  3. Reduction

  4. Smelting

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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?

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

  1. $Cu$ and $Ag$

  2. $Si$ and $Ge$

  3. $Ti$ and $Ni$

  4. All of these

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Correct Option: A

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

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

  1. Anode

  2. Cathode

  3. 1 and 2 both

  4. None of these

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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 

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

  1. Liquidation

  2. Electrolytic process

  3. Van Arkel method

  4. Calcination

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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:

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

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

Show answer
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.

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

  1. True

  2. False

  3. Cannot be determined

  4. None of the above

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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:

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

  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

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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?

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

  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

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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.

The method used in metallurgy to refine the impure metal is:

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

  1. Mond process

  2. Van Arkel process

  3. Liquation

  4. All of the above

Show answer
Correct Option: D
Explanation:
$\text{Mond Method:}$ It is specially used for Ni. The vapour phase refining of Ni on heating in a stream of CO forms volatile $Ni(CO) _4$. These vapours when subjected to still higher temperature, decompose to give pure metal.

$\text{Liquation Method:}$ Pb, Sn, Bi, Zn etc are purified by this method. The metal has a low melting point and impurities have a high melting point. In an open hearth, the metal is heated to its melting point and metal melts down and impurities remain behind.

$\text{Van Arkel method}$: This method is used for ultrapure metals like Ti, Zr etc. The metal is converted into its volatile stable compound such as $TiI _4$, leaving behind impurities. The stable volatile compound thus formed is decomposed to get the pure metal.

Hence, option D is correct.