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

Stainless steel is made from _________.

  1. iron and carbon

  2. iron and chromium, nickel and manganese

  3. iron, carbon and metals (chromium, nickel and manganese)

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

Yes, it is made by mixing iron with carbon, chromium, nickel and manganese.

Multiple choice

Which of the following has the minimum carbon content?

  1. Steel

  2. Pig iron

  3. Wrought iron

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

Wrought iron is the purest form of commercial iron, containing the lowest percentage of carbon (typically less than 0.08 percent). In contrast, pig iron and cast iron have much higher carbon contents.

Multiple choice

Iron articles rust because of the formation of

  1. ferrous chloride

  2. a mixture of ferrous and ferric hydroxides

  3. ferric sulphate

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

Rust is a hydrated iron oxide, typically represented as a mixture of hydrated ferrous and ferric hydroxides or oxides formed in the presence of oxygen and moisture.

Multiple choice

Photographic plates are covered with black paper because

  1. the cellulose acetate of the paper must remain fresh

  2. sunlight is easily absorbed by black paper and it helps develop the film

  3. the silver bromide present on the plate is very sensitive to light and black paper prevents contact with light

  4. the conversion of silver bromide to metallic silver is essential
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Photographic film contains silver halides (like silver bromide) which decompose upon exposure to light; black paper prevents this premature exposure.

Multiple choice

In which of the following method, are metals coated with Cr and Ni?

  1. Sacrificial Protection

  2. Alloying

  3. Electroplating

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

Coating the surface with metals like tin, chromium, nickel, etc. by electroplating, is also utilized to prevent corrosion. Steel cans are protected by relatively un-reacted tin, and works well, as long as, the thin tin layer is complete

Multiple choice

Which of the following statements is/are false? A. Copper is used for making anticorrosive wires that are used in electrical industries. B. Constantan consists of 60% copper and 40% tin. C. In the manufacturing of dye-stuffs, paints zinc dust is used as reducing agent.

  1. Only A

  2. Only B

  3. Only C

  4. Only A and B

  5. Only B and C
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Constantan is a copper-nickel alloy usually consisting of 55% copper and 45% nickel. Hence, statement B is only false.

Multiple choice

Assertion (A): In the extraction of iron, there is no need of roasting if pure hematite is used as an ore. Reason (R): The final product of the roasting process is FeO3 in the extraction of iron. Choose the correct opinion.

  1. A is true, but R is false.

  2. A is false, but R is true.

  3. Both A and R are true.

  4. Both A and R are false.

  5. None of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In the extraction of iron, in roasting step all pure haematite is converted to ferrous oxide (FeO) that combines with oxygen and form Fe2O3. So, the final product of the roasting step is FeO3 in the extraction of iron, and hence  there is no need of roasting.

Multiple choice

Which of the following statements is/are incorrect? P. The refining of impure Sn involves Sweating process followed by Electrorefining. Q. Calcined mixture of dolomite and powder of ferro-silicon is heated to 1200 degree C in a closed container. Mg is vaporised and collected in a condenser. The process is called as Pidgeon process. R. Galena and Willemite are sulphide ores.

  1. Only P

  2. Only P and Q

  3. Only Q and R

  4. Only Pand R

  5. Only R

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

Galena (PbS) is the sulphide ore of lead. Willemite (ZnSiO3) is the silicate ore of zinc. Hence, statement R is only incorrect.