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

Why pure gold is always alloyed with other metals?

  1. To increase its softness

  2. To decrease its reactivity

  3. To increase its shine

  4. To increase its hardness

  5. To make it malleable
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Gold is a dense, soft, shiny, malleable and ductile metal. Gold readily creates alloys with many other metals. The extreme malleability, ductility and softness of pure gold make it practically useless for jewellery applications. The addition of alloying elements (other metals) to gold is used to increase the toughness and hardness of the metal. 

Multiple choice

What is the process of dipping an iron article in molten zinc to form a protective coating of zinc called?

  1. Cyanide process

  2. Gold plating

  3. Corrosion

  4. Tinning

  5. Galvanization
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Galvanization is the process of applying a protective zinc coating to steel or iron, in order to prevent rusting. Although galvanization can be done with electrochemical and electrodeposition processes, the most common method in current use is hot dip galvanization, in which steel parts are submerged in a bath of molten zinc.

Multiple choice

What is the reason for this?

Lead can float on the surface of mercury.

  1. Mercury is very reactive.

  2. Lead is very reactive.

  3. Lead is more denser than mercury.

  4. Mercury is more denser than lead.

  5. Mercury is lighter than lead.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

It is because lead is less denser than mercury. Mercury is very heavy weighing 13.6 times to that of volume of water. Stone, iron, and even lead can float on its surface.

Multiple choice

What is the reason for this?

When a magnesium ribbon and a copper wire are wound around iron nails in two test tubes named A and B respectively, then  the tubes are left exposed to air for a few days, we notice that the iron nail in tube A does not rust but it rusts in the tube B.

  1. Copper prevents corrosion in tube A

  2. Reaction occurs between magnesium and copper

  3. Copper prevents corrosion in tube B

  4. Magnesium is more electropositive than iron
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Invar also known as FeNi36 is a nickel iron alloy notable for its uniquely low coefficient of thermal expansion (CTE or ل). The name comes from the word invariable referring to its lack of expansion or contraction with temperature changes.

Multiple choice

A sponge can be compressed easily whereas an iron rod cannot. Which among the following is the possible reason for this?

  1. Particles are tightly packed in iron rods whereas loosely packed in sponge.

  2. Particles of sponge possess weak intermolecular force of attraction whereas that of iron rod possess strong force.

  3. A sponge has minute holes in which air is trapped whereas no such holes are present in an iron rod.

  4. A sponge possesses the property of elasticity whereas an iron rod does not.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A sponge has minute holes in which air is trapped. When we press it, the air is expelled out and we are able to compress it.

Multiple choice

Coating of iron with zinc is known as

  1. galvanization

  2. electroplating

  3. ionization

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

Galvanization is the specific process of coating iron or steel with zinc to prevent rusting. The zinc acts as a sacrificial metal, corroding in place of the iron. Electroplating is a broader term that can coat any metal onto another surface.

Multiple choice

Consider the following statements:

  1. Stainless steel pans are usually provided with copper bottoms because copper is easier to clean than the stainless steel.
  2. The process of conversion of water into vapours without reaching the boiling point is called evaporation.

Which of the given statements is/are incorrect?

  1. Only (1)

  2. Only (2)

  3. Both (1) and (2)

  4. Neither (1) nor (2)
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Statement (1) is incorrect. Stainless steel pans are usually provided with copper bottoms because copper is a better conductor of heat than the stainless steel. Statement (2) is correct. The process of conversion of water into vapours without reaching the boiling point is called evaporation.