Tag: metallurgy

Questions Related to metallurgy

(a) Thermite welding process exploits the difference in reactivity of different metals.
(b) Zinc spelter is used as cathode in electrolyte refining process of zinc.
(c) Iron is generally refined by electrolytic reduction process
(d) Iron is alloyed with other metals and carbon, only to prevent corrosion.
Which of the following options regarding the above statements is correct?

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

  1. a and d

  2. b and c

  3. only a

  4. a, b and c

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Correct Option: C
Explanation:

Thermite welding process exploits the difference in reactivity of different metals. Pure zinc rod is used as cathode while a block of impure zinc spelter is used as anode. Iron is generally refined by smelting process.Iron is alloyed with other metals and carbon prevents the oxidation of iron and formation of rust.

The percentage of carbon is the least in :

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

  1. White cast iron

  2. Grey cast iron

  3. Wrought iron

  4. Steel

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Correct Option: D
Explanation:

1: wrought iron carbon content 0.05-0.25%
2 : white and grey iron is the type of cast iron which contain 2.14-6.67% carbon. 
3: steel contain 0.008-2.14% carbon So D. Steel has least Carbon %

Iron reacts with _______.

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

  1. cold water

  2. hot water

  3. water

  4. none of the above

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Correct Option: D
Explanation:

Iron reacts with oxygen and ions to make rust. after rust formation, it does not allow Iron to react with water.

Oven coke is used throughout the world in blast furnaces to make:

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

  1. gold

  2. biomass

  3. iron

  4. all of above

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Correct Option: C
Explanation:

Coke is a fuel with few impurities and a high carbon content, usually made from coal. Oven coke is used throughout the world in blast furnaces to make iron.

The purpose of smelting an ore is to _________ it.

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

  1. oxidise

  2. reduce

  3. neutralise

  4. none of these

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Correct Option: B
Explanation:

Purpose of smelting an ore is to reduce it. $Fe _{2}O _{3}$ is ore and $C$ is reductant.

In smelting, $ Fe _{2}O _{3}+3C\rightarrow 2Fe+3CO$.

Which of the following processes involves 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. $2PbS +3O _2 \rightarrow 2PbO + 2SO _2$

  3. $Fe _2O _3 + 3C \rightarrow 2Fe + 3CO$

  4. $Al _2O _3.2H _2O \rightarrow Al _2O _3 + 2H _2O$

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Correct Option: C
Explanation:

In smelting, Iron ore is reduced to iron.

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

In the extraction of iron, slag is produced which is

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

  1. $CaSiO _3$

  2. $FeSiO _3$

  3. $CO$

  4. $MgSiO _3
    $

Show answer
Correct Option: A
Explanation:
During extraction of iron, soda time is added in furnace because it combines with gangue to form slag
$CaO+SliO _2  \rightarrow CaSiO _3$
Basic        Acidic          Slag

Which of the following methods is not involved in metallurgy of iron?

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

  1. Calcination

  2. Smelting

  3. Concentration of ore

  4. None of these

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Correct Option: D
Explanation:
(1) Calcination is the process in which the ore is heated below its melting point, either in the absence or in a limited supply of air, in an aim to drive off volatile expunges, moisture, water of hydrates and organic matter from the ore. All ores are minerals but all minerals are not ores.

(2)Smelting is a process when a metal which is more reactive than copper needs to be extracted. For example, zinc is more reactive than copper so it has to be extracted by smelting.

(3)Ores are solid material from which a pure metal can be obtained. The process of removal of unwanted material from the ore is known as concentration or dressing or benefaction of ores.

So Calcination, Smelting, Concentration of ore all the processes used in metallurgy.

Iron is an essential nutrient for plants, which absorb it from the soil. Iron deficiency is often found in wet, clayey soils that have a high content of:

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

  1. carbonate

  2. chloride

  3. phosphate

  4. sulphate

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Correct Option: A
Explanation:

Iron and carbon occurs combinedly. Iron ore contains carbon percentage more. In clay, wet soils carbon content is more. So, Iron deficiency is there. In reactions carbon changes to carbonate.

Iron is used in different forms, like, cast iron, steel, and alloys. The iron-carbon diagram is the basis for the branch of science known as:

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

  1. ferrous metallurgy

  2. stereochemistry

  3. carbon metallurgy

  4. organic chemistry

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Correct Option: A
Explanation:

The percentage of Iron and Carbon determine whether it is cast Iron, Pig Iron, Steel or Alloys. Hence this is known as Ferrous Metallurgy. The main contribution is given by Iron as every type of Iron contains more than 90% of Iron.