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

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.

Multiple choice

Which of the following product will obtained at cathod during electrolysis of aq CuSO4 with copper electrodes?

  1. Copper metal

  2. Copper ions

  3. O2 gas

  4. H2 gas
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

For every copper ion discharged at the cathode, a copper ion is released into the solution at the anode. The sulphate and the hydroxyl ions remain as spectator ions. The total number of copper and sulphate ions remain constant throughout. Assuming that no evaporation takes place, the blue color of the copper sulphate is maintained throughout.

Multiple choice

The catalyst used in Haber process is

  1. Pt

  2. Ni

  3. Fe

  4. V2O5
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The Haber Process combines nitrogen from the air with hydrogen derived mainly from natural gas (methane) into ammonia. The reaction is reversible and the production of ammonia and  is exothermic.The catalyst is actually slightly more complicated than pure iron. It has potassium hydroxide added to it as a promoter - a substance that increases its efficiency.

Multiple choice

Galvanized iron is the iron plate coated with _______.

  1. Diamond

  2. Copper

  3. Magnesium

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

Galvanization is the process of applying a protective zinc coating to steel or iron to prevent rusting. The zinc acts as a sacrificial anode to protect the underlying metal.

Multiple choice

The chemical reagent used for leaching of gold and silver ores is

  1. sodium hydroxide

  2. potassium cyanide

  3. sodium thiosulphate

  4. sodium bicarbonate

  5. none of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

This option is correct because the leaching of gold means gold cyanidation of gold and for silver ores cyanidation of silver. Potassium cyanide (KCN) is used for extraction of gold and silver with respect to water to form soluble coordination complexes (K[Ag(CN)2], K[Au(CN)2]).

Multiple choice

The process of protecting iron by coating with zinc is _____________.

  1. smelting

  2. galvanization

  3. rusting

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

In current use, the term refers to the coating of steel or iron with zinc. This is done to prevent rusting of the ferrous item. The value of galvanizing stems from the relative corrosion resistance of zinc, which, under most service conditions, is considerably less than those of iron and steel.