Chemistry · Science General

Metallurgical Processes

1,403 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 geography in the land of kerala introduction to metallurgy occurrence of metals study of kerala

The waste, or slag, that comes out at the bottom of a blast furnace for making iron from its ore, is no thrown away. It is used for making?

  1. Dental powder

  2. Roads

  3. Plastics

  4. Glass moulds
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Solution:- (B) Roads

Slag is valuable raw material for preparation of macadam materials and mineral blinders serving as a base for asphalt concrete mixture and manufacturing of cement emulsions, which are widely used in road paving.

Multiple choice geography in the land of kerala introduction to metallurgy occurrence of metals study of kerala

Pig iron can be converted into steel by removing a lot of carbon contained in it, in a/ an:

  1. electrolytic chamber

  2. bessemer converter

  3. blast furnace

  4. pyrite burner
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Solution:- (B) bessemer converter

The Bessemer process was the first inexpensive industrial process for the mass production of steel from molten pig iron before the development of the open hearth furnace. The key principle is removal of impurities from the iron by oxidation with air being blown through the molten iron.

Multiple choice geography in the land of kerala introduction to metallurgy occurrence of metals study of kerala

Calcium silicate slag formed in extraction of iron :

  1. prevents the reoxidation of molten iron.

  2. catalyses the combustion of carbon
  3. reduces $CO _2$ to $CO$ at the bottom of the furnace

  4. is used in cement industry
Reveal answer Fill a bubble to check yourself
A,D Correct answer
Explanation

Slag formed in extraction of iron is consists of $CaSiO _3$ which is further used for making cement.
Also, formation of this slag prevents the re-oxidation of molten iron.

Multiple choice chemistry chemical effects of electric current applications of electrolysis electroplating extraction of metals by electrolysis

The electrical process of coating an inexpensive conductor with a metal is called electroplating.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Electroplating is a process that uses electric current to deposit/reduce dissolved metal cations so that they form a thin coherent metal coating on an electrode.

It is used to coat a relatively mundane metal, such as copper, with a thin layer of another, more precious metal, such as gold or silver. 

Hence, option $\text{A}$ is correct.
Multiple choice chemistry chemical effects of electric current applications of electrolysis electroplating extraction of metals by electrolysis

Chromium plating is done to make the object scratch proof and appear shiny.

  1. True

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

Chromium plating is a technique of electroplating in which a thin layer of chromium is coated onto a metal object. The layer is decorative (shiny), provide corrosion resistance, ease cleaning procedures, and increase surface hardness (scratch resistance).


Hence, option A is correct.

Multiple choice physics chemical effects of electric current applications of electrolysis electroplating extraction of metals by electrolysis

To protect iron from corrosion and rusting , it is electroplated with 

  1. Zinc

  2. Chromium

  3. Nickel

  4. Aluminum
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Iron is coated with a more active metal like Zinc. This is a sacrificial method. If the rusting conditions are met, zinc rusts before iron and prevents iron from rusting. Zinc makes a protective layer with Zn(OH)2 and ZnCO3

Multiple choice chemistry chemical effects of electric current applications of electrolysis electroplating extraction of metals by electrolysis

The process of depositing a thin layer of desired metal over another metal by passing an electric current through some electrolyte is called :

  1. electric shielding

  2. electric polishing

  3. electric coating

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

Electroplating is the application of electrolytic cells in which a thin layer of metal is deposited onto an electrically conductive surface.


Hence, option D is correct.

Multiple choice physics chemical effects of electric current applications of electrolysis electroplating extraction of metals by electrolysis

Electroplating does not help

  1. fine finish to the surface

  2. shining appearance

  3. metals to become hard

  4. protect metals against corrosion
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Electroplating is primarily used to change the surface properties of an object like appearance, corrosion protection, lubricity etc.  Thus, electroplating does not help in making the metals become hard. 

Multiple choice physics chemical effects of electric current applications of electrolysis electroplating extraction of metals by electrolysis

Chromiumhas a shiny appearance and lt does not corrode

  1. True

  2. False

  3. Ambiguous

  4. Data insufficient
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Answer is A.
Electroplating is a very useful process. It is widely used in industry for coating metal objects with a thin layer of a different metal. The layer of metal deposited has some desired property, which the metal of the object lacks. For example, chromium plating is done on many objects such as car parts, bath taps, kitchen gas burners, bicycle handlebars, wheel rims and many others.
Chromium has a shiny appearance. It does not corrode. It resists scratches. However, chromium is expensive and it may not be economical to make the whole object out of chromium. So the object is made from a cheaper metal and only a coating of chromium over it is deposited.
Hence, electroplating of chromium is done on objects like water taps and cycle bell to give them a shiny appearance and prevent them from corrosion. The statement is true.

Multiple choice physics chemical effects of electric current applications of electrolysis electroplating extraction of metals by electrolysis

In electroplating of the silver spoon with gold, the silver spoon is cleaned with a dilute acid solution to remove the  _________  from its surface.

  1. oxide layer

  2. chloride layer

  3. silver layer

  4. gold layer
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The silver spoon is cleaned with a dilute acid solution to remove the oxide layer from its surface and washed in running water until it is free from the acid.

Multiple choice metallic and electrolytic conduction electrolysis chemical reactions electrochemistry chemistry

The first step in the extraction of Cu from copper pyrites is?

  1. Reduction by carbon

  2. Electrolysis of ore
  3. A Roasting of ore in $O _2$

  4. Magnetic separation
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Copper pyrites (CuFeS2) contain iron and copper sulfides. The initial step in extracting copper from copper pyrites is roasting the ore in the presence of oxygen to remove excess sulfur as sulfur dioxide and convert iron sulfide into iron oxide.

Multiple choice metallic and electrolytic conduction electrolysis chemical reactions electrochemistry chemistry

Which of the following is/are always true electroplating ?

  1. Copper is used as cathode

  2. Cathode always gins weight while anode always loses weight

  3. Iron is coated with nickel or chromium to prevent from rusting.

  4. Ammeter reading during. electroplating steadily decreases.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In electroplating, the object to be plated is the cathode. While the cathode gains weight, the anode only loses weight if it is made of the metal being plated (sacrificial anode). Option A is the most general correct statement regarding the setup.

Multiple choice chemistry principles of metallurgy concentration of ore concentration of ores general principles of metallurgy

What is the process of leaching in case of low grade copper ores?

  1. Leaching is carried out with $NaOH$ and $O _2$
  2. Leaching is carried out with $NaCN$
  3. Leaching is carried out with acids in presence of $O _2$

  4. Leaching is carried out by boiling the ore with water
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Leaching of low grade copper ores is carried out with acid or bacteria, when copper goes into solution as $Cu^{2+} _{(aq) }+ H _{2(g)}\rightarrow Cu _{(s)}+2H^+ _{(aq)}$