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 separation of matter crystals and crystallisation filtration and crystallisation other methods of separation

After purification by crystallization, copper sulphate crystals can be obtained by :

  1. filtration

  2. passing through funnel

  3. evaporation to dryness

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

Impure copper sulphate is dissolved in water and heated till saturation. It is then cooled and crystals of pure copper sulphate are formed. These crystals are then separated by filtration and then dried.

Multiple choice chemistry separation of matter crystals and crystallisation filtration and crystallisation other methods of separation

What are the characteristics of the solvent used during purification of copper sulphate by crystallization?

  1. Not dissolve the substance at room temperature

  2. Dissolve the impurities at room temperature

  3. Does not dissolve the impurities at high temperature

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

Choosing an appropriate solvent is the important process of crystallisation, as crystallisation works only when a proper solvent is used. It is important to choose a solvent that will not dissolve the substance at room temperature. But as the temperature of the solvent increases, the solubility of the solute also increases. At the same time, the impurities that are present must either be soluble in the solvent at room temperature or must be insoluble in the solvent at a high temperature. If the solvent is not hot when the dissolution is carried out, too much solvent will be used, leading to diminished yield.

Multiple choice chemistry separation of matter crystals and crystallisation filtration and crystallisation other methods of separation

During concentration (saturation), copper sulfate solution is constantly stirred to :

  1. ensure uniform evaporation

  2. prevent formation of a solid crust

  3. both a and b

  4. it is not stirred during saturation
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

To concentrate the filtrate of impure copper sulphate, the china dish containing filtrate is heated gently with constant stirring. This is done to ensure uniform evaporation and to prevent formation of a solid crust. 

Multiple choice chemistry separation of matter crystals and crystallisation filtration and crystallisation other methods of separation

Why is dilute sulphuric acid added during crystallization of copper sulphate?

  1. Prevent hydrolysis of copper sulphate

  2. Prevent crystallization of copper sulphate

  3. Enhance formation of large crystals

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

To crystallise copper sulphate, it is dissolved in water and a small quantity of dilute sulphuric acid is added to prevent the hydrolysis of copper sulphte. The impurities left behind in the solution are removed by filtration.

Multiple choice chemistry separation of matter crystals and crystallisation filtration and crystallisation other methods of separation

Arrange the following steps in crystallisation of copper sulphate.
A. Dissolve it in minimum amount of water.
B. Take some (approximately 5 g) impure sample of copper sulphate in a china dish.
C. Cover the solution with a filter paper and leave it undisturbed at room temperature to cool slowly for a day.
D. Evaporate water from the copper sulphate solution so as to get a saturated solution.
E. Filter the impurities out.

  1. A, C, B, D, E

  2. B, D, A, C, E

  3. B, A, D, E, C

  4. B, A, E, D, C
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The correct order of steps in crystallisation of copper sulphate is B, A, D, E, C.
B. Take some (approximately 5 g) impure sample of copper sulphate in a china dish.
A. Dissolve it in minimum amount of water.
D. Evaporate water from the copper sulphate solution so as to get a saturated solution.
E. Filter the impurities out.
C. Cover the solution with a filter paper and leave it undisturbed at room temperature to cool slowly for a day.

Multiple choice chemistry basic analytical techniques partition coefficients solvent extraction separation methods

How is scrap-iron separated from other wastes in a scrap yard?

  1. Sublimation

  2. Magnetic separation

  3. Handpicking

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

Waste materials supplied to factories contain a number of scrap metals including iron ore. so, in factories, scrap iron is separated from the heap of waste materials by using big electromagnets fitted to a crane. 

Multiple choice physics transfer of heat applications of heat conduction applications of insulation clothes - our necessity

The reason for providing copper bottoms in steel pans is :

  1. aesthet, carly looks good

  2. that copper is better conductor than steel

  3. that copper is not a good conductor than steel

  4. None of the above

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Copper bottoms are provided in steel pans because copper is better conductor of heat than steel.

Thermal conductivity of copper is highest ($38600w/mK$) while that of steel is lowest ($1245w/mK$).

Multiple choice chemistry mix and separate dry methods of separation process of separating components of a mixture method of separation

Which technique could be used to obtain the elements X and Y from the compound $XY$?

  1. Filtration

  2. Distillation

  3. Electrolysis

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

To separate elements X and Y from the compound XY we have to break it into ions,

and the process of breaking compound into its ions are known as electrolysis.

Multiple choice chemistry mix and separate dry methods of separation process of separating components of a mixture method of separation

Winnowing is useful only when:

  1. two solids have different melting points

  2. two solids have different boiling points

  3. two solids have different magnetic properties

  4. two solids have different weights
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

winnowing is used to separated heavier and lighter components of a mixture by wind or by blowing air.This process is done by the farmers to separated lighter husk particles from heavier grain particles.

Multiple choice physics heat - measurement introduction to temperature application of various thermometric scales different types of thermometers

Iron glows in red colour when it is heated to very high temperature. The reason for this is :

  1. Heat we supply consumes red colour at high temperature

  2. Mechanical energy is being converted into heat energy

  3. All metals glow in red colour when heated

  4. Heat energy is being converted into light energy
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Iron glows in red colour when it is heated to very high temperature cause heat energy is being converted into light energy.

Multiple choice chemistry production of metals extraction of aluminium metallurgy of aluminium extraction of metals by electrolysis

(a) Roasting and calcination are the two processes to reduce the metal oxides to the respective metals.
(b) Magnesium is extracted from its ore by electrolytic reduction process.
(c) Cryolite is used in metallurgy of aluminium in order to increase the fusibility and conductivity
(d) I Hall's process bauxite is leached with the help of ${Na} _{2}{CO} _{3}$.
Which of the following options regarding the above statements is correct?

  1. a, b and c

  2. b, c and d

  3. c and d

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

(b) Magnesium is extracted from its ore by electrolytic reduction process.
(c) Cryolite is used in metallurgy of aluminium in order to increase the fusibility and conductivity
(d) I Hall's process bauxite is leached with the help of ${Na} _{2}{CO} _{3}$. statements are correct. The concentrated ore is converted into metal oxide by calcination or roasting.

Multiple choice chemistry production of metals extraction of aluminium metallurgy of aluminium extraction of metals by electrolysis

State the function of fluorspar in the metallurgy of aluminium.

  1. to increase conductivity

  2. to decrease conductivity

  3. to increase ductility

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

Pure alumina melts at about $2000^oC$ and is a bad conductor of electricity. If fused cryolite and fluorspar is added, the mixture melts at $900^0C$ and solution becomes a good conductor of electricity. 

Multiple choice chemistry production of metals extraction of aluminium metallurgy of aluminium extraction of metals by electrolysis

The electrolyte used in electrolytic refining of impure aluminium is __________.

  1. $AI _2O _{3} + CaF _{2}$
  2. $Na _{3}AlF _{6} + CaF _{2}$
  3. $Al _2O _{3}, Na _{3}AlF _{6} and CaF _{2}$

  4. Any aluminium salt is molten state
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In the metallurgy of aluminium, purified $Al _2O _3$ is mixed with $Na _3AlF _6$ or $CaF _2$ which lowers the melting point of the mix and brings conductivity.

Multiple choice chemistry production of metals extraction of aluminium metallurgy of aluminium extraction of metals by electrolysis

In the electrolytic reduction of alumina, the electrolyte is covered with coke powder because, it __________.

  1. prevents oxidation of aluminium formed

  2. reacts with aluminium forming aluminium carbide

  3. prevents heat loss from the electrolyte

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

The electrolytic mixture is sprinkled with coke to prevent the anode's oxidation by the oxygen evolved

Also, more material to the top of the anode is continuously added in the form of briquettes made from coke and pitch. The lost heat from the smelting operation is used to bake the briquettes into the carbon form required for reaction with alumina.
Therefore, $C$ is correct