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 chemistry principles and processes of isolation of elements refining of metals basics of metallurgy basic metallurgical processes

In Poling process, Hydrocarbon gases escaping from the poles act as _____ agents.

  1. reducing

  2. oxidation

  3. both

  4. none
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Poling is a process in which the impure metal containing oxide as impurities is purified. It is melted and stirred with green poles of wood. Hydrocarbon gases escaping from the poles act as reducing agents and reduce the oxide impurities e.g., impurity of Cu$ _2$O which is reduced to metallic copper by poling.
$Cu _2O + CO \rightarrow 2Cu + CO _2 \uparrow$
$Cu _2O + H _2 \rightarrow 2Cu + H _2O$

Multiple choice chemistry principles and processes of isolation of elements refining of metals basics of metallurgy basic metallurgical processes

In polling, wood gas is responsible for the removal of volatile impurities.

  1. True

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

True. Polling is used for converting Copper Oxide $(Cu _2O)$ to Copper $(Cu)$. When ore is heated with wood poles, the poles release charcoal, shoot and gas. The gas released reduces $CuO$ to $Cu$. So the gas takes away impurities. 

Multiple choice chemistry principles and processes of isolation of elements refining of metals basics of metallurgy basic metallurgical processes

Which of the following methods is used to remove lead present in silver ?

  1. Cupellation

  2. Distillation

  3. Poling

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

Cupellation is a process of separation of gold or silver from impurities by melting the impure metal in a cupel (a flat porous dish made of refractory or high-temperature resistant material  ) and then directing a blast of hot air on it in a special furnace. The impurities, including lead,copper, tin, and other unwanted metals, are oxidized and partly vaporized and partly absorbed into the pores of the cupel.

Multiple choice chemistry principles and processes of isolation of elements refining of metals basics of metallurgy basic metallurgical processes

Poling process:

  1. reduces $SnO _2$ to Sn

  2. oxidizes impurities like iron and removes as scum

  3. uses green poles

  4. uses brown poles
Reveal answer Fill a bubble to check yourself
A,B,C Correct answer
Explanation

Poling: A refining process of crude metal for removing metal oxide impurities by stirring molten metal in a ladle with a pole of green wood (poles).


In the poling process, the reduction of oxides to metal atom will be done.

Ex: Extraction of copper from copper oxide and Sn from $SnO _2$.

Hence options A,B & C are correct.

Multiple choice geography mineral and energy resources - i iron and steel industries iron and steel industry mineral based industries

Bokaro Steel was established with the assistance of __________.

  1. Germany

  2. Soviet Union

  3. UK

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

  • Bokaro steel plant is located in the district of Bokaro in the state of Jharkhand.
  • It was founded with the assistance of Soviet Union or USSR.
  • It was founded in the year 1964.  It is merged with the state-owned Steel Authority of India Limited (SAIL).

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

The process of depositing thin layer of a metal over an another metal with a help of electric current is called :

  1. electrorefining

  2. electroplating

  3. thermoplating

  4. none of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Electroplating is the process of plating one metal onto another, for decorative purposes or to prevent corrosion of a metal. 

Multiple choice chemistry chemical changes applications of electrolysis electroplating extraction of metals by electrolysis

The process of electrolysis is used in:

  1. extraction of metals

  2. electroplating

  3. refining of metals

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

Answer is D.
Electrolysis has wide applications in industries. Some of the important applications are, as follows, 
(i) Production of hydrogen by electrolysis of water. 
(ii) Manufacture of heavy water. 
(iii) The metals like K, Mg, Al, etc., are obtained by electrolysis of fused electrolytes. 
(iv) Non-metals like hydrogen, fluorine, chlorine are obtained by electrolysis. 
(v) In this method pure metal is deposited at cathode from a solution containing the metal ions, etc. 
(vi) Compounds like NaOH, KOH, white lead, etc. are synthesised by electrosynthesis method.
(vii) Electroplating: The process of coating an inferior metal with a superior metal by electrolysis is known as electroplating. 
Hence, the options A, B and C are correct.

Multiple choice chemistry chemical changes applications of electrolysis electroplating extraction of metals by electrolysis

The most durable metal plating on iron to protect against corrosion is:

  1. tin plating

  2. zinc plating

  3. copper plating

  4. nickel plating
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Metal plating protects the iron against corrosion by forming a sacrificial layer. This metal layer itself gets oxidize instead of iron and thus protects the iron itself. 


For a metal to be used as plating, its oxidation should be preferred over iron and thus should have lower reduction potential than iron. 

Among the given options, zinc has a lower reduction potential than iron and thus can be used for plating. The process is called galvanization.

Hence, option B is correct. 

Multiple choice chemistry chemical changes applications of electrolysis electroplating extraction of metals by electrolysis

In the electrolysis of molten $Al _2O _3$ with inert electrodes:

  1. Al is oxidized at anode to $Al^{3+}$
  2. $O _2$ gas is produced at anode
  3. $O^{2-}$ is reduced at cathode
  4. $O$ is oxidized at anode
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The electrodes are inert so that they do not involve the electrode reactions but transfer electrons through them. Since the silvery metal i.e. $Al$ is produced at cathode.

At cathode: $Al^{3+}+3e^- \longrightarrow Al$
At anode, $O _2$ bubbles off.
At anode; $2O^{2-}\longrightarrow O _2+4e^-$
The cell reaction: $2Al _2O _3\longrightarrow 4Al+3O _2$

Multiple choice chemistry chemical changes applications of electrolysis electroplating extraction of metals by electrolysis

By selecting electrolyte as sodium argentocyanide for electroplating of the metal article with silver. Which of the following condition ensures that deposit is smooth, firm and long-lasting?

  1. low direct current should be passing for long time

  2. low indirect current should be passing for long time

  3. low direct current should be passing for short time

  4. low indirect current should be passing for long time.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

For high-quality electroplating, a low current density is required to ensure a smooth, uniform, and firm deposit. A high current would result in a rough, powdery, or non-adherent deposit.