Tag: thermodynamic principles of metallurgy

Questions Related to thermodynamic principles of metallurgy

Due to extreme high pressure, iron exist in:

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

  1. liquid form

  2. solid form

  3. molten form

  4. gaseous form

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Correct Option: B
Explanation:

Under extremely high-pressure conditions, the iron is becomes more solid because in high pressure its molecular density increases.So, its becomes harder.

Which of the following metals can be used for sharp casting?

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

  1. Iron

  2. Copper

  3. Aluminium

  4. Silver

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Correct Option: A
Explanation:

Casting is a manufacturing process by which a liquid material is usually poured into a mold, which contains a hollow cavity of the desired shape, and then allowed to solidify. The solidified part is also known as a casting, which is ejected or broken out of the mold to complete the process. Iron is the best metal amongst the given options for sharp casting.

(a) Cast iron is very hard and brittle because of higher carbon content.
(b) Iron obtained from the blast furnace is know as pig iron.
(c) The carbon content in wrought iron is the least.
(d) The melting point of cast iron is higher than that of wrought iron.
Which of the following regarding the above statements is correct?

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

  1. a, b and c

  2. c and d

  3. only b

  4. only d

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Correct Option: A
Explanation:

Cast iron is iron that has been shaped by being poured into a cast. It has 5% or more carbon, and the carbon separates out into flakes. This reduces the tensile strength, but not the compressive strength. Pig iron is iron as cast after smelting from ore and has a high carbon content and is an intermediate product for making steel. Wrought iron is iron with a low carbon content.Pig iron and cast iron have have a lower melting point than wrought iron or steel.

The reaction which is not associated with the middle region of blast furnace during smelting is _______ .

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

  1. ${CO} _{2}+C\rightarrow 2CO$

  2. $Ca{CO} _{3}\rightarrow CaO+{CO} _{2}$

  3. $CaO+Si{O} _{2}\rightarrow CaSi{O} _{3}$

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

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Correct Option: D
Explanation:

A blast furnace is a type of metallurgical furnace used for smelting to produce industrial metals, generally iron, but also others such as lead or copper. With the first being that preheated blast air blown into the furnace reacts with the carbon in the form of coke to produce carbon monoxide and heat.
$2 C _{(s)} + {O _2} _{(g)} \rightarrow 2 CO _{(g)}$
All other reactions are associated with the middle region of blast furnace during smelting.The hot carbon monoxide is the reducing agent for the metal ore and reacts with the metal oxide to produce molten metal and carbon dioxide. 

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

Identify the compound $X$ :

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

  1. $FeO$

  2. $ Fe _{2}O _{3}$

  3. $Fe _{3}O _{4}$

  4. All of these

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Correct Option: B
Explanation:

The reaction of iron oxide with aluminium is used to join railway tracks. 


Aluminium powder is used for the thermite reaction as it reacts with iron $(II) $ oxide to give molten $Fe$.

Hence the correct option is B.

Which of the following gives black precipitate with $H _{2}S$ ?

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

  1. Cupric chloride

  2. Cadmium chloride

  3. Zinc chloride

  4. Ferric chloride

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Correct Option: D
Explanation:

Iron from blast furnace is Pig Iron. It is intermediate to form Wrought Iron or Cast Iron. It is the first product from Blast Furnace. After applying some chemical reactions, pure iron will come.

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

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

  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$

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Correct Option: C
Explanation:

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

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

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

  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

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Correct Option: B
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.

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

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

  1. Galvanic reaction

  2. Thermal reaction

  3. Thermite reaction

  4. Combination reaction

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Correct Option: C
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.

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

The electrolytic reduction technique is used in the extraction of:

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

  1. Metalliods

  2. Highly electro positive metals

  3. Transition metals

  4. Highly electronegative metals

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Correct Option: B
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.