Tag: chemistry

Questions Related to chemistry

$Fe _3O _4$ is the chemical formula of :

thermodynamic principles of metallurgy general principles and processes of isolation of elements metallurgy chemistry

  1. monazite

  2. magnetite

  3. haematite

  4. bauxite

Show answer
Correct Option: B
Explanation:

$Fe _3O _4$ is the chemical formula of magnetite.

Magnetite is the mineral of Iron.
Magnetite is the most magnetic of all the naturally-occurring minerals on Earth.
The chemical IUPAC name is Iron(ll,lll) oxide and the common chemical name is ferrous-ferric oxide.
So answer is B.

Reduction to free metal: some of the methods commonly used to get free metal from the concentrates ore are below.
Smelting: The process of extracting a metal in the state of fusions is called smelting. In this process the ore is mixed with carbon and heated in suitable furnace
Electrolytic reduction process: This process is used in the extraction of the alkali and alkaline earth metals, zinc and aluminium.
Self reduction process: The sulphide ores of less electropositive metals like Hg, Pb, Cu etc., are heated in air so asto convert part of the ore into oxide or sulphate which then reacts with the remaining sulphide ore to give the metal.

After partial roasting, the sulphide of copper is reduced by :
thermodynamic principles of metallurgy general principles and processes of isolation of elements metallurgy chemistry

  1. Reduction by carbon

  2. Electrolysis

  3. Self-reduction

  4. Cyanide process

Show answer
Correct Option: C
Explanation:
In the extraction of copper, metal is formed in the Bessemer converter due to self reduction as

${ Cu } _{ 2 }S+2{ Cu } _{ 2 }O\rightarrow 6Cu+S{ O } _{ 2 }$

Which metal among the following is present in human blood?

thermodynamic principles of metallurgy general principles and processes of isolation of elements metallurgy chemistry

  1. Titanium

  2. Mercury

  3. Gold

  4. Iron

Show answer
Correct Option: D
Explanation:

Iron is present in human blood.

Reduction to free metal: some of the methods commonly used to get free metal from the concentrates ore are below.
Smelting: The process of extracting a metal in the state of fusions is called smelting. In this process, the ore is mixed with carbon and heated in a suitable furnace
Electrolytic reduction process: This process is used in the extraction of the alkali and alkaline earth metals, zinc and aluminium.
Self-reduction process: The sulphide ores of less electropositive metals like Hg, Pb, Cu etc., are heated in the air so as to convert part of the ore into oxide or sulphate which then reacts with the remaining sulphide ore to give the metal.

In the metallurgical extraction of zinc from ZnO, the reducing agent used is :
thermodynamic principles of metallurgy general principles and processes of isolation of elements metallurgy chemistry

  1. $CO$

  2. $SO _{2}$

  3. $CO _{2}$

  4. $NO$

Show answer
Correct Option: A
Explanation:
In the metallurgical extraction of zinc from ZnO, the reducing agent used is C/CO.

$ZnO + C \rightarrow   Zn + CO$
$ ZnO + CO \rightarrow  Zn + CO _2$

Which of the following reaction represents the action of steam on heated iron?

thermodynamic principles of metallurgy general principles and processes of isolation of elements metallurgy chemistry

  1. $3Fe+4H _2O\rightarrow Fe _3O _4+4H _2$

  2. $2Fe+3H _2O\rightarrow Fe _2O _3+3H _2$

  3. $Fe+H _2O\rightarrow FeO+H _2$

  4. $2Fe+H _2O+O _2\rightarrow Fe _2O _3+H _2$

Show answer
Correct Option: A
Explanation:
When steam is passed over a red hot iron to form the ferric oxide and hydrogen gas is released.

The action of steam on heated iron is represented as follows:

$3Fe+4H _2O\rightarrow Fe _3O _4+4H _2$

Hence, option A is the correct answer.

Which of the following is purest form of iron?

thermodynamic principles of metallurgy general principles and processes of isolation of elements metallurgy chemistry

  1. Wrought iron

  2. Pig iron

  3. Steel

  4. None of these

Show answer
Correct Option: A
Explanation:

Wrought iron is purest form of iron.

The smelting of iron in a blast furnace involves all the following processes except :

thermodynamic principles of metallurgy general principles and processes of isolation of elements metallurgy chemistry

  1. combustion

  2. reduction

  3. slag formation

  4. sublimation

Show answer
Correct Option: D
Explanation:

The smelting of iron in a blast furnace involves all the following processes except Sublimation.

Sublimation is the transition of a substance directly from the solid to the gas phase without passing through the intermediate liquid phase.

Which of the following methods is used in the concentration of haematite ore?

thermodynamic principles of metallurgy general principles and processes of isolation of elements metallurgy chemistry

  1. Hydraulic washing

  2. Magnetic separation

  3. Froth floatation process

  4. None of these

Show answer
Correct Option: B

Which of the following is not an illustration of a smelting method?

thermodynamic principles of metallurgy general principles and processes of isolation of elements metallurgy chemistry

  1. $2NaCl(fused)+electric \ energy\rightarrow 2Na+{Cl} _{2}$

  2. ${Al} _{2}{O} _{3}+3C \rightarrow 2Al+3CO$

  3. $2ZnS+3{O} _{2}\rightarrow 2ZnO+2{SO} _{2}$

  4. $CuO+{H} _{2}\rightarrow Cu+{H} _{2}O$

Show answer
Correct Option: A
Explanation:

It is the process by which a metal is obtained, either as the element or as a simple compound, from its ore by heating beyond the melting point, ordinarily in the presence of oxidizing agents, such as air, or reducing agents, such as coke. An oxidising agent is used in case of Al,Zn and Cu and so sodium reaction is not a smelting method.

Reduction to free metal: some of the methods commonly used to get free metal from the concentrates ore are below.
Smelting: The process of extracting a metal in the state of fusions is called smelting. In this process, the ore is mixed with carbon and heated in a suitable furnace
Electrolytic reduction process: This process is used in the extraction of the alkali and alkaline earth metals, zinc and aluminium.
Self-reduction process: The sulphide ores of less electropositive metals like Hg, Pb, Cu etc., are heated in the air so as to convert part of the ore into oxide or sulphate which then reacts with the remaining sulphide ore to give the metal.

The metal extracted by electrolysis of its fused salt is :
thermodynamic principles of metallurgy general principles and processes of isolation of elements metallurgy chemistry

  1. $Fe$

  2. $Pb$

  3. $Na$

  4. $Cu$

Show answer
Correct Option: C
Explanation:

Na can not be obtained by electrolysis of the aqueous solution of salt as hydrogen ions have higher reduction potential than $Na^+$ so hydrogen ions will reduce first and we will get hydrogen gas instead of Na metal by electrolysis of the aqueous solution,

So sodium metal is extracted by electrolysis of its fused salt.

$NaCl \rightarrow Na^+ + Cl^-$


At cathode:
$Na^+ + e^- \rightarrow Na$