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 salts salts and their classification acids, bases and salts chemistry
State which of the following methods is generally used for preparing the $Cu(NO _3) _2$ salts.
1: Neutralisation-insoluble base & dilute acid.
2: Neutralisation-alkali & dilute acid.
3: Simple displacement-active metal & dilute acid.
4: Direct combination.           
5: Precipitation [double decomposition].

  1. 1

  2. 2

  3. 3

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

Copper reacts with nitric acid to form copper nitrate.


$3Cu+8HNO _3 \rightarrow 3Cu(NO _3) _2+4H _2O+2NO$

Hence, the correct option is simple displacement-active metal & dilute acid.  


Hence, the correct option is $(C)$

Multiple choice archimedes' principle fluid pressure properties of matter physics

Why an iron nail floats on mercury but it sinks in water?

  1. Density of iron is more than that of mercury, but less than that of water.

  2. Density of iron is less than that of mercury, but more than that of water.

  3. Density of iron is less than that of mercury and water

  4. Density of iron is more than that of mercury, water.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

This is because density of mercury is more than that of water.
An object floats on a liquid, if its density is lower than that of the liquid. 
The density of iron nail is more than that of the water but less than that of mercury.

Multiple choice chemistry ionic equilibrium introduction to ionic equilibria in solution ionic equilibrium in solution ionisation of weak acids and weak bases

The process in which metal surface is made inactive is called:

  1. passivation

  2. galvanizing

  3. corrosion

  4. pickling
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Passivation involves creation of an outer layer of shield material that is applied as a microcoating, created by chemical reaction with the base material, or allowed to build from spontaneous oxidation in the air.

Galvanization is the process of applying a protective zinc coating to steel or iron, to prevent rusting

Corrosion is a natural process, which converts a refined metal to a more chemically-stable form, such as its oxide. 

Pickling is the process of preserving or expanding the lifespan of food by either anaerobic fermentation in brine or immersion in vinegar. 
Multiple choice physics capacitance capacitors in parallel combination of capacitors capacitors in parallel and series

In order to increase the capacity of parallel plate condenser one should introduce between the plates, a sheet of

  1. mica

  2. tin

  3. copper

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

mica as it is having higher conductivity$.$

So$,$ increase the capacity of parallel plate condenser one should introduce between the plates$,$ a sheet of $mica.$
Hence,
option $(A)$ is correct answer.

Multiple choice chemistry p- block elements-i study of aluminium chloride study of aluminium structure of some compounds

Some properties of aluminium are listed.
1 It has mechanical strength.
2 It is resistant to corrosion.
3 It has a low density.
4 It conducts heat.
Which three properties make aluminium useful for making the bodies of aircraft?

  1. $1, 2$ and $3$
  2. $1, 2$ and $4$
  3. $1, 3$ and $4$
  4. $2, 3$ and $4$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Solution:- (A) $1, \; 2$ and $3$

Aluminium is useful in making of aircraft bodies due to its mechanical strength, low density and corrosion resistance.

Multiple choice chemistry p- block elements-i study of aluminium chloride study of aluminium structure of some compounds

Which of the following methods can be used for the preparation of anhydrous aluminium chloride?

  1. Heating ${Al Cl _3.6 H _2 O}$

  2. Heating a mixture of alumina and coke in a current of dry chlorine

  3. Passing dry HCl gas over heated aluminium powder

  4. Passing dry chlorine over heated aluminium
Reveal answer Fill a bubble to check yourself
B,C,D Correct answer
Explanation

Anhydrous aluminium chloride can be prepared by the following methods:
(B) Heating a mixture of alumina and coke in a current of dry chlorine.
$Al _2O _3+3C+3Cl _2 \rightarrow 2AlCl _3+3CO\uparrow$


(C) Passing dry HCl gas over heated aluminium powder.
$2Al+6HCl \rightarrow 2AlCl _3+3H _2$

(D) Passing dry chlorine over heated aluminium.
$2Al+3Cl _2 \rightarrow 2AlCl _3$

It can not be obtained by heating of $AlCl _3.6H _2O$, because $AlCl _3$ is covalent and hence when the water of crystallisation is evaporated, $AlCl _3$ will react with the water to form the hydroxide.

Multiple choice geography rivers, coasts and glaciation rivers rivers and their work exogenic forces

What is rust?

  1. Chemical reaction between oxygen and iron

  2. Chemical reaction between carbon dioxide and iron

  3. Chemical reaction between alkalis and iron

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

The iron in the rock comes in contact with water and chemical reaction takes place between iron and oxygen. Hence,a reddish coloured layer forms on the rocks. This is called rust.

Multiple choice chemistry environmental chemistry biochemistry and the environment green chemistry strategies to control environmental pollution and green chemistry

Faraday has developed a plating process to make high-performance chrome coatings from trivalent chromium instead of highly toxic hexavalent chromium. This is an application of:

  1. Green revolution

  2. Green chemistry

  3. waste management

  4. revolution resource recovery
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Faraday has developed a plating process to make high-performance chrome coatings from trivalent chromium instead of highly toxic hexavalent chromium. It involves the production of alternate product which is more friendly to environment. Hence, this is an application of Green chemistry.

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

While obtaining pure copper sulphate from an impure sample what will finally be obtained in the china dish?

  1. Impurities of the sample are left behind in the china dish

  2. Copper sulphate

  3. Water droplets

  4. Chine dish remains empty
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

When crystallisation is performed to obtain pure copper sulphate from an impure sample, finally crystals of copper sulphate is obtained in the chine dish.

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

Why crystallisation is used as a method of obtaining pure $CuSO _4$ from impure sample?

  1. Because $CuSO _4$ is a liquid
  2. Because $CuSO _4$ is a solid
  3. Because $CuSO _4$ is a gas

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

Crystallisation is a method used to purify solids. $CuSO _4$ is solid, hence it can be obtained as in a pure cystal form from impure samples using cystallisation.

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

The copper sulphate solution is heated gently on a water bath for :

  1. proper mixing of the sample

  2. evaporation of water

  3. dissolving the copper sulphate in solution

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

Pure copper sulphate is obtained from an impure sample by re-crystallization. The sample is mixed in water and filtered to remove impurities. It is then heated gently on a water bath for evaporation of water. Thus, a saturated solution is obtained.

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

To crystallize copper sulphate, it is dissolved in water and a small quantity of ................. is also added.

  1. concentrated nitric acid

  2. dilute hydrochloric acid

  3. dilute sulphuric acid

  4. dilute nitric acid
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

To crystallise copper sulphate, water is dissolved 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

When are the crystals of copper sulphate obtained?

  1. when hot acidic copper sulphate solution is cooled gradually.

  2. when cold acidic copper sulphate solution is heated gradually.

  3. when hot acidic copper sulphate solution is cooled suddenly.

  4. when cold acidic copper sulphate solution is heated suddenly
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

When hot acidic $ copper : sulphate$ solution is cooled gradually, the crystals of  $ copper : sulphate$ are obtained.

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

Why crystallisation is used for obtaining pure copper sulphate from an impure sample rather than simple evaporation?

  1. Some impurities may remain dissolved in the solution even after filtration. On evaporation, these may contaminate the solid

  2. Because crystallisation is comparatively easier than evaporation

  3. Because crystallisation is comparatively faster

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

Crystallisation technique is better than simple evaporation technique as some solids decompose and some impurities may remain dissolved in the solution even after filtration. On evaporation, these contaminate the solid.