Tag: chemistry

Questions Related to chemistry

If steel is heated bright red hot and is then cooled slowly, the process is called:

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

  1. quenching

  2. annealing

  3. tempering

  4. smelting

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Correct Option: B
Explanation:

Annealing is heat process whereby a metal is heated to a specific temperature/color and then allowed to cool slowly. This softens the metal which means it can be cut and shaped more easily. Mild steel is heated to a red heat and allowed to cool slowly.

Electromagnets are used to concentrate _______ ores :

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

  1. mercury

  2. copper

  3. Iron

  4. sulphur

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Correct Option: C
Explanation:

Iron ores have the electromagnetic property so they are concentrated by this method. An electromagnet is a type of magnet in which the magnetic field is produced by an electric current. The magnetic field disappears when the current is turned off.

Iron :

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

  1. is a metal i.e. magnetic in nature

  2. forms an alloy called steel

  3.  is brittle(cast iron)

  4. All of these

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Correct Option: D
Explanation:

Iron is the metal of transition series which oxidizes in air to give hydrated iron oxides. Crude iron metal is produced in blast furnaces where ore is reduced by coke to pig iron which has high carbon content.

The metal which is present in our body in red blood corpuscles and whose deficiency in the body causes anaemia is

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

  1. zinc

  2. arsenic

  3. iron

  4. tin

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Correct Option: C
Explanation:

Iron is the metal present in our body in red blood corpuscles and its deficiency in the body causes anaemia.

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

Show answer
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

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

Show answer
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

Show answer
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

Show answer
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.