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 metals alloys and crystals chemistry elements and compounds alloys and their properties chemical bonding and structure

Which of the following properties of elements can be modified by the formation of alloys?

  1. Resistance to corrosion

  2. Toughness

  3. Malleability & ductility

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Alloys are used in some applications, where their properties are superior to those of the pure component elements, for a given application. This can include improvement in corrosion resistance (like stainless steel), toughness (like carbon-iron alloys) and malleability-ductility (like wrought iron).

Multiple choice chemistry elements and compounds alloys and their properties metals, alloys and crystals chemical bonding and structure

Which of the following methods can be used for the preparation of alloys?

  1. Melting a mixture of metals

  2. Simultaneous eletrolytic deposition of metals

  3. By mixing the aqeous solutions of the metal salts

  4. Both 1 and 2
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Alloys can either be produced by melting a mixture of metals or simultaneous eletrolytic deposition of metals. This is because alloys are interstitial compounds, and have one atom of a metal inside the solid structure of another atom. This requires mixing in an efficient way, and not just normal physical conditions. 

Multiple choice chemistry elements and compounds alloys and their properties metals, alloys and crystals chemical bonding and structure

Raney Nickel is finely divided nickel obtained by digesting alloys of $Ni/Al $ over $NaOH$.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Raney nickel is a fine-grained solid composed mostly of nickel derived from a nickel aluminum alloy
The alloy is treated with a concentrated solution of sodium hydroxide. The simplified leaching reaction is:
$2Al + 2NaOH + 6 H _2O \rightarrow  2 Na[Al{(OH)} _4] + 3 H _2$
After this process, leaching is done to form raney nickel which is powder and spongey.
Given statement is true.
Multiple choice chemistry elements and compounds alloys and their properties metals, alloys and crystals chemical bonding and structure

Statement 1 : A mixture of pure metals is called an alloy. The melting point of an alloy will be lower than either of the component metal.
Statement 2 : The new bonds are weaker.

  1. <p>Both Statement 1 and Statement 2 are correct and Statement 2 is the correct explanation of Statement 1</p>

  2. <p>Both Statement 1 and Statement 2 are correct and Statement 2 is not the correct explanation of Statement 1</p>

  3. <p>Statement 1 is correct but Statement 2 is not correct</p>

  4. <p>Statement 1 is not correct but Statement 2 is correct</p>

  5. <p>Both the Statement 1 and Statement 2 are not correct</p>
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Both Statement 1 and Statement 2 is correct and Statement 2 is the correct explanation of Statement 1.


A mixture of pure metals is called an alloy. The melting point of an alloy will be lower than either of the component metal because the new bonds are weaker.

Hence, the correct option is A.

Multiple choice chemistry elements and compounds alloys and their properties metals, alloys and crystals chemical bonding and structure

Tinned iron sheets are used for making boxes for fruits, oils, vegetables etc.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Tinning is the process of thinly coating sheets of wroughtiron or steel with tin, and the resulting product is known as tinplate. While once more widely used, the primary use of tinplate now is the manufacture of tin cans. Formerly, tinplate was used for cheap pots, pans and other holloware. It has an extremely beautiful metallic luster as well as excellent properties in corrosion resistance, solderability, and weldability. 

So it's true.

Multiple choice chemistry elements and compounds alloys and their properties metals, alloys and crystals chemical bonding and structure

Tin is used for making fusible alloys.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A fusible alloy is a metal alloy capable of being easily fused, i.e. easily meltable, at relatively low temperatures. The most widely used fusible alloys contain high percentages of bismuth, combined with lead, tin, cadmium, indium and other metals. Bismuth has an impact on the melting point, as well as the growth and shrinkage characteristics of the alloys.

Multiple choice chemistry elements and compounds alloys and their properties metals, alloys and crystals chemical bonding and structure

Statement 1: A mixture of pure metals is called an alloy. The melting point of an alloy will be lower than either of the component metals
Statement 2: The new bonds are weaker.

  1. Statement 1 and Statement 2 are correct and Statement 2 is the correct explanation of Statement 1

  2. Both the Statement 1 and Statement 2 are correct, but Statement 2 is not the correct explanation of Statement 1.

  3. Statement 1 is correct, but Statement 2 is not correct.

  4. Statement 1 is not correct, but Statement 2 is correct.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Both statement right and statement $2$ are correct Explanation.

Note : [alloy is the mixture of different metals .each metal having different size and structural arrangements. The different sizes of atoms in an alloy make their arrangement less regular than a pure metal. This makes the bonds between the atoms weaker and lower melting point.

Multiple choice chemistry elements and compounds alloys and their properties metals, alloys and crystals chemical bonding and structure

Surface chemists design alloys for specific functions in everyday life.
Which of the following does not demonstrate a benefit of using an alloy?

  1. Gold is mixed with copper or silver to make a less expensive form that can be used in jewelry.

  2. Smaller atoms of one metal are incorporated into the structure of larger metal atoms to reduce malleability and improve strength of the structure.

  3. Densities of metals are closely matched to increase desirable properties without increased cost.

  4. The conductivity has been eliminated due to the stronger bonding of the different types of metals.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Ans: (B) Smaller atoms of one metal are incorporated into the structure of large metal atom to redue malleability and improve strength of structure.

Note : - Smaller atoms have greater ratios of surface area to volume which means greater ratio of atom boundary to dislocation.

Multiple choice chemistry elements and compounds alloys and their properties metals, alloys and crystals chemical bonding and structure

Steel, composed of carbon and iron, is an example of an interstitial alloy.
Which of the following choices represents the best explanation for the fact that steel is harder and stronger than pure iron?

  1. Carbon atoms are more reactive with oxygen than iron atoms. This prevents the steel from forming rust.

  2. Carbon atoms are smaller than iron atoms. Carbon atoms fill the spaces between iron atoms, making the structure more rigid.

  3. Carbon atoms form strong bonds with other carbon atoms. This forms a protective layer on the surface of steel.

  4. Both carbon and iron are good conductors of electricity. This makes steel harder and stronger than pure iron.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Ans : (B) Carbon atoms are smaller than iron atoms. Carbon atoms fill the spaces between iron atom, making the structure $\%$ more rigid.
Note : - Steel is interstitial alloy of iron and carbon, due to smaller size of carbon, it easily fit between the metal atoms (iron) and provide Extra bonding to neighbouring atom, which makes alloy harder stronger (rigid).
Multiple choice chemistry elements and compounds alloys and their properties metals, alloys and crystals chemical bonding and structure

When items of jewellery made of base metals like copper, iron or nickel are placed in a solution containing a compound of gold, a film of gold is deposited by:

  1. cooling to $5$ degree centigrade

  2. adding acid

  3. heating

  4. passing an electric current
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Electroplating is the process in which a layer of a metal is deposited on metallic or non-metallic electrode by electrolysis in an electrolytic cell.

When items of jewellery made of base metals like copper, iron or nickel are placed in a solution containing a compound of gold, a film of gold is deposited by the process of electroplating which  requires passing an electric current in it.
Hence option D gives the correct answer.

Multiple choice chemistry elements and compounds alloys and their properties metals, alloys and crystals chemical bonding and structure

Which of the following is a steel that is resistant to acids?

  1. Nickel alloy steel

  2. Molybdenum steel

  3. Stainless steel

  4. Cobalt alloy steel
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Molybdenum can be obtained from the minerals molybdenite, wulfenite and powellite. It is also obtained as a byproduct during tungsten and copper mining and processing. It has one of the highest melting points of all pure elements; however it is not resistant to acids.Hence, molybdenum steel is also not resistant to acids.

Hence option B is correct answer.

Multiple choice chemistry change around us physical changes changes and their classification physical changes

Two changes are stated below:
(i.) A piece of magnesium gives of bright flames when burned.
(ii). A piece of iron glows red when heated strongly.
 Which of these is a physical change?

  1. Only i

  2. Only ii

  3. Both i and ii

  4. Neither i nor ii
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

When magnesium is burnt, it reacts with the heat and gives bright flames and this change cannot be reversed.
When iron heated strongly it turns red. When heating is stopped it cools and get backs to its original form. So this is a physical change.

Multiple choice chemistry change around us physical changes changes and their classification physical changes

A filler is a substance added to make a material less expensive, or for:

  1. Changing its acidity

  2. Changing its physical properties

  3. Reducing its chemical activity

  4. Increasing its anti-rusting power
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A filter is a substance added to make a material less expensive or for changing its physical properties.

Filter are added to alter and improve the physical and mechanical properties of plastics it does not affect the structure arrangement of substance.