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

Aluminium metal is extracted by the electrolysis of its _________.

  1. molten Chlorides

  2. molten Sulphide

  3. molten oxide

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

Aluminium is extracted from bauxite (Al2O3) by the Hall-Héroult process, which involves electrolysis of molten aluminium oxide dissolved in cryolite. Molten chlorides are not the source - bauxite is an oxide ore. The key is that alumina must be molten for electrolysis to work.

Multiple choice

The tape in a cassette which is plyed in a tape recorder is coated with

  1. copper sulphate

  2. ferromagnetic powder

  3. silica

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

Cassette tapes use magnetic tape coated with ferromagnetic powder (such as ferric oxide or chromium dioxide). This coating allows sound to be recorded and played back through electromagnetic encoding and pickup by the tape recorder head.

Multiple choice

When iron rusts, its weight __________.

  1. increases

  2. decreases

  3. no change

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

When iron rusts, it combines with oxygen from the air to form iron oxide (rust). Since oxygen is being added to the iron, the total weight increases. This is contrary to what many might intuitively think, as rust often appears flaky and worn away, but chemically, mass is being added to the iron.

Multiple choice

What is the corrosion of iron called?

  1. Roasting

  2. Rusting

  3. Rating

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

Rusting is the specific term for the corrosion of iron, where iron reacts with oxygen and moisture to form iron oxide (Fe₂O₃·nH₂O). This is a type of oxidation reaction that weakens the metal over time. Roasting is a metallurgical process, while rating is not related to corrosion.

Multiple choice

Which of the following options is the process in which a carbonate ore is heated strongly in the absence of air to convert it into metal oxide?

  1. Calcination

  2. Roasting

  3. Electrolysis

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

Calcination is the process of heating a carbonate ore strongly in the absence of air. This converts carbonate ores like zinc carbonate (ZnCO3) into metal oxides (ZnO) and carbon dioxide. Roasting is similar but done in the presence of air, producing sulfur dioxide for sulfide ores. Electrolysis is an entirely different process using electricity.

Multiple choice

Why is it difficult to break an iron nail?

  1. Because of high kinetic energy

  2. Because of strong force of attraction

  3. Because of high mechanical energy

  4. Because of indivisibility of its particles
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

It is difficult to break an iron nail because of strong force of attraction.