Chemistry · Science General

Metallurgical Processes

1,436 Questions

This section explores key metallurgical processes including ore concentration, pyrometallurgy, and metal refining. It also covers corrosion and the properties of refractory materials. These chemistry questions are relevant for engineering and science entrance tests.

Pyrometallurgy furnacesMetal refining techniquesCorrosion protection methodsOre concentrationAuto reduction process

Metallurgical Processes Questions

Multiple choice chemistry changes around us effects of oxidation reactions in daily life corrosion of metals electroplating and its application

What is corrosion?

  1. When metal is gradually destroyed through chemical reactions

  2. When metal is created through chemical reactions

  3. When a redox reaction takes place

  4. When a metal is destroyed after exposure to a gas

  5. When a solid is destroyed through chemical reactions
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Corrosion occurs when a redox reaction takes place.

Corrosion is a natural process, which converts a refined metal to a more chemically-stable form, such as its oxide, hydroxide, or sulfide. It is the gradual destruction of materials by chemical and/or electrochemical reaction with their environment.
It also gradually destroys the element through chemical reactions

Hence, the correct options are $A$ and $C$

Multiple choice chemistry changes around us effects of oxidation reactions in daily life corrosion of metals electroplating and its application

Which of the following metals has been used for building boats because it has resistance to corrosion by sea water?

  1. Copper

  2. Nickel

  3. Fungsten

  4. Titanium
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Titanium is used for building boats.

Inert metals which do not react with gases in air seen as oxygen are found to be non-corrosive.
It is corrosion resistance because it forms stable, protective, oxide film when $Ti$ is exposed to oxide film.

Multiple choice chemistry changes around us effects of oxidation reactions in daily life corrosion of metals electroplating and its application

In the rusting of iron, iron has been:

  1. oxidised

  2. reduced

  3. vaporised

  4. decomposed
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
In corrosion, metal is oxidised by loss of electrons to oxygen to form metal oxide. In rusting of iron, at one spot of the iron object oxidation occurs and that spot behaves as an anode.
Anode:    $Fe(s)  →  Fe^{2+}(aq) + 2e^-  $
Cathode: $4e^- + 4H^+(aq) + O _2(aq)  →  2H _2O(l)$
Multiple choice chemistry changes around us effects of oxidation reactions in daily life corrosion of metals electroplating and its application

Iron nails rust fast when used for fixing plates or strips of aluminium on a building. Similarly, a water pipe made of iron corrodes faster when connected to a pipe of copper. This happens because of the?

  1. Greater wetting of iron

  2. Easier flow of electrons to iron

  3. Higher rusting power of iron

  4. Chemical reduction of iron
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

This is due to higher rusting power of iron.

When iron pipe is connected to copper corrosion is caused by self induced current created. The current is generated due to difference in electrical potential. The water act as a weak electrolyte.

Multiple choice chemistry nitrogen and sulfur sulfur and its oxides acid deposition natural resources- air, water and land

A solution of chromium oxide in concentrated sulphuric acid is used for cleaning glass in laboratories because it:

  1. Removes sand particles

  2. Oxidises grease

  3. Dissolves glass

  4. Reacts with dust
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Because a solution of chromium oxide in sulfuric acid (also known as a sulfochromic mixture or chromosulfuric acid) is a powerful oxidizing agent, it can be used to clean laboratory glassware, particularly of otherwise insoluble organic residues.They oxidize the grease present on the glass surfaces and hence thus it can be cleaned.

Multiple choice stefan's law black body radiation heat transfer thermal properties physics

A blackened steel plate is put in a dark room after being heated up to a high temperature. A white spot on the plate appears. 

  1. brighter than the plate

  2. as bright as the plate

  3. dull as compared to the plate

  4. appears to be yellow
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

According to Kirchhoff's law of radiation, good absorbers are good emitters. A white spot (which is a poor absorber/emitter compared to the blackened surface) will emit less radiation at the same temperature, making it appear darker or less bright than the surrounding blackened surface.

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

In which of the following pair of metals, both are commercially extracted from their respective ores by carbon reduction method?

  1. $Zn$, $Cu$
  2. $Fe$, $Cu$
  3. $Sn$, $Zn$
  4. $Al$, $Ag$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Tin and zinc are commercially extracted from their respective ores by carbon reduction method.
The oxide ores of tin and zinc are reduced with carbon to form metals.

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

In the metallurgy of iron using blast furnace, the slag is :

  1. $FeSiO _3$
  2. $CaSiO _3$
  3. $CaCO _3$
  4. $CaSO _3$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Slag is a glass like by product left over after a desired metal has been separated from its ore.Slag is usually a mixture of metal oxides and silicon dioxide.These slags can contain metal sulfides and elemental metals.

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

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

  1. quenching

  2. annealing

  3. tempering

  4. smelting
Reveal answer Fill a bubble to check yourself
B Correct answer
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.

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

Iron :

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

  2. forms an alloy called steel

  3. is brittle(cast iron)

  4. All of these
Reveal answer Fill a bubble to check yourself
D Correct answer
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.

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

(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?

  1. a, b and c

  2. c and d

  3. only b

  4. only d
Reveal answer Fill a bubble to check yourself
A Correct answer
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.