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

Which of the following processes is involved in the smelting process?

  1. $ZnCO _{3} \rightarrow ZnO + CO _{2}$
  2. $PbS + 3O _{2} \rightarrow 2PbO + 2SO _{2}$
  3. $Fe _{2}O _{3} + 3C \rightarrow 2Fe + 3CO$
  4. $ Al _{2} O _{3}. 2H _{2}O \rightarrow Al _{2}O _{3} + 2H _{2}O$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In smelting process, ferric oxide gets reduced to Iron with the help of coke. The redox reaction is given by the option C.

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

In the metallurgical extraction of iron, which of the following processes takes place in reverberatory furnace?

  1. Conversion of iron oxide to iron

  2. Conversion of cast iron to wrought iron

  3. Conversion of cast iron to steel

  4. Conversion of pig iron to cast iron
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Wrought iron or malleable iron is the purest form of commercial iron and is prepared from cast iron by oxidising impurities in a reverberatory furnace lined with haematite.

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

Compound $X$ and aluminium are used to join railway tracks.
Name the reaction.

  1. Galvanic reaction

  2. Thermal reaction

  3. Thermite reaction

  4. Combination reaction
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The reaction is called thermite reaction, in which $Al$ reduces the oxide of another metal as it forms stronger and more stable bonds with oxygen than the other metal.

$Fe _2O _3 + 2 Al \rightarrow  2 Fe + Al _2O _3$

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

The electrolytic reduction technique is used in the extraction of:

  1. Metalliods

  2. Highly electro positive metals

  3. Transition metals

  4. Highly electronegative metals
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Oxides of strong elecropositive metals such as K, Ca, Na, Al and Mg are very stable. It is difficult to reduce them into metallic state by carbon reduction.
Such metals are extracted by passing electricity through their fued chlorides/oxides/hydroxides.
So electrolytic extraction technique is used in extraction of highly electro positive metals.

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

Which of the following oxides cannot be reduced by coke?

  1. $Cu _2O,\: K _2O$
  2. $Fe _2O,\: ZnO$
  3. $CaO, \: K _2O$
  4. $PbO,\: Fe _3O _4$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Oxides of strong elecropositive metals such as $K, Ca, Na, Al$ and $Mg$ are very stable. It is difficult to reduce them into metallic state by carbon reduction.
Such metals are extracted by passing electricity through their fused chlorides/oxides/hydroxides.

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

Which of the following is not correctly matched?

  1. Red bauxite - Purification by Serpeck's method

  2. Iron from haematite - Carbon monoxide reduction

  3. Calamine - Carbonate ore
  4. $FeSiO _3$ - Slag obtained in the extraction of copper
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Red bauxite is purified by Bayer's process, not Serpeck's method. Serpeck's method is typically used for the purification of white bauxite (containing silica as impurity).

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

Which one of the following is not a method of concentration of ore? 

  1. Electromagnetic separation

  2. Smelting

  3. Gravity separation

  4. Froth floatation process
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The process of removal of unwanted materials from the ore is known as ore concentration. 


Froth floatation, electromagnetic separation, and gravity separation are few of the processes used for ore concentration.

 
Smelting, however, is a process of heating the ore in order to extract the base metal. 


Hence B is the correct answer

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

Name the substance which remains in a test tube after heating ferrous sulphate.

  1. $Fe _2O _3$
  2. $Fe _2S$
  3. $Fe _2(SO _4) _3$

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

Heating farrow sulfate in a test tube following reaction takes place

$FeSO _4.7H _2O\rightarrow Fe SO _4+7H _2O$
$2Fe SO _4\rightarrow Fe _2O _3+SO _2+SO _3$
Both $SO _2$ and $SO _3$ are gases that colorless and evolved out 
Only $Fe _2O _3$  that is ferric oxide which reddish brown in colour remained in the fort tube ,so the answer is $Fe _2O _3$ that is ferric oxide

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

Heating mixture of $Cu _2O$ and $Cu _2S$ will give:

  1. $Cu+SO _2$
  2. $Cu+SO _3$
  3. $CuO+CuS$
  4. $Cu _2O+S$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Reaction of the process:


$ 2Cu _2 O+ Cu _2S \overset{\Delta}{\longrightarrow} 6Cu+SO _2$

The heating mixture of Cu$ _2$O and Cu$ _2$S will give Cu and SO$ _2$ mixture.

Hence, the correct option is $A$