Tag: thermodynamic principles of metallurgy

Questions Related to thermodynamic principles of metallurgy

The percentage of carbon is the least in :

  1. White cast iron

  2. Grey cast iron

  3. Wrought iron

  4. Steel


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 _______.

  1. cold water

  2. hot water

  3. water

  4. none of the above


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:

  1. gold

  2. biomass

  3. iron

  4. all of above


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.

  1. oxidise

  2. reduce

  3. neutralise

  4. none of these


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?

  1. $ZnCO _3 \rightarrow ZnO + CO _2$

  2. $2PbS +3O _2 \rightarrow 2PbO + 2SO _2$

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

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


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

  1. $CaSiO _3$

  2. $FeSiO _3$

  3. $CO$

  4. $MgSiO _3
    $


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?

  1. Calcination

  2. Smelting

  3. Concentration of ore

  4. None of these


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:

  1. carbonate

  2. chloride

  3. phosphate

  4. sulphate


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:

  1. ferrous metallurgy

  2. stereochemistry

  3. carbon metallurgy

  4. organic chemistry


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.

Magnetic ceramics or ferrites contain compounds of iron. These have been used:

  1. in panels for solar cells

  2. as memory elements in computers

  3. for building water-desalinators on ships

  4. for making transformers


Correct Option: B
Explanation:

Magnetic ceramics or ferrites are used to store computer data in the residual magnetic fields of hard ferrite cores.