Chemistry · General Awareness

Chemistry of Metals and Alloys

1,851 Questions

Review the physical and chemical properties of various metals and their common alloys. This collection covers industrial applications, metallurgical processes, and practical uses of elements like silicon and boron. Practice these questions to strengthen your chemistry fundamentals for exams.

Properties of metalsCommon alloysIndustrial metallurgyChemical applications

Chemistry of Metals and Alloys Questions

Multiple choice

Among the following which one is used as a brazing flux for aluminium in automobile parts?

  1. Lithium borohydride

  2. Lithium bromide

  3. Lithium carbide

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

Lithium chloride is produced by treatment of lithium carbonate with hydrochloric acid. Lithium chloride is mainly used for the production of lithium metal by electrolysis of a LiCl/KCl melt at 600 °C. LiCl is also used as a brazing flux for aluminium in automobile parts. It is used as a desiccant for drying air streams.

Multiple choice

Phosphorus is a

  1. nonmetal

  2. metal

  3. gas

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

Phosphorus is a nonmetallic element located in Group 15 of the periodic table. It exists in several allotropic forms (white, red, black) and is essential for life, being a component of DNA, RNA, and ATP.

Multiple choice

Which of the following are examples of amphiprotic metals?

  1. Si
    1. Zn
    2. Al
    3. Pb
    4. Na

  1. 1 and 2

  2. 1, 2 and 3

  3. 2 and 5

  4. 2, 3 and 4

  5. 3, 4 and 5
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

An amphiprotic species is a molecule or ion that can both accept and donate protons. A common example of an amphiprotic metal is  Zinc: In acid: ZnO + 2H+ → Zn2+ + H2O. In base: ZnO + H2O + 2OH- → [Zn(OH)4]2- Almunium: In acid : Al2O3 + 3 H2O + 6 H3O+(aq) → 2 [Al(H2O)6]3+(aq) In base: Al2O3 + 3 H2O + 2OH-(aq) → 2 [Al(OH)4]-(aq) Lead: In acid : PbO + 2 HCl → PbCl2 + H2O In base : PbO + 2 NaOH + H2O → Na2[Pb(OH)4]

Multiple choice

Which among the following metals is used for joining wires in electronic circuit boards?

  1. Silver

  2. Lead

  3. Mercury

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

Solder, which is primarily composed of lead (or lead-tin alloy), is the standard metal used for joining wires and components in electronic circuit boards due to its low melting point and good conductivity. While silver and gold are excellent conductors, they are too expensive for routine soldering use, and mercury is a liquid at room temperature making it impractical for permanent connections.

Multiple choice

Which metal is extracted from sea water?

  1. Potassium

  2. Magnesium

  3. Aluminium

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

Magnesium is the only metal among these options that is commercially extracted from seawater on a large scale. The process involves electrolysis of magnesium chloride obtained from seawater, where magnesium is present at about 1.3 g/kg. Magnesium compounds are abundant in ocean water, while potassium comes primarily from mineral deposits (sylvite), aluminium from bauxite ore, and beryllium from bertrandite and beryl minerals.

Multiple choice

Which of the following statements is/are incorrect? A. Copper is used for making wires used in electrical industry and for water and steam pipes. B. German silver contains Cu 50-60% and Ni 40–50%. C. Zinc dust is used as a reducing agent in the manufacture of dye-stuffs, paints, etc. and in several organic and inorganic synthesis reactions.

  1. A only

  2. B only

  3. C only

  4. A and B

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

A. Copper has very good anti-corrosive property and is used for making wires used in electrical industry and for water and steam pipes. B. German silver contains Cu 25-30%, Zn 25-30% and Ni 40–50%. C. Zinc dust is used as a reducing agent in the manufacture of dye-stuffs, paints, etc. and in a several organic and inorganic synthesis reactions.

Multiple choice

Which of the following is/are fusible alloy(s)? P. Newton’s alloy Q. Jean Darcet’s alloy R. Dow’s alloy

  1. P only

  2. Q only

  3. R only

  4. P and Q

  5. Q and R
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Fusible alloys are generally composed of Bi, Pb and Sn. They melt at comparatively low temperatures, below the melting point of tin. Examples are- Newton’s alloy (contains 50% Bi, 31.25% Pb and 18.75% Sn), Jean Darcet’s alloy (contains 50% Bi, 25% Pb and 25% Sn), etc. Dow’s alloy or Dow metal is an example of light metal alloys. Dow metal contains 93.8% Mg, 6% Al and 0.2% Mn.

Multiple choice

The composition of Field’s metal is

  1. 51% In, 32.5% Bi, 16.5% Sn

  2. 50% Bi, 25–28% Pb, 22–25% Sn

  3. 50% Bi, 26.7% Pb, 13.3% Sn,10% Cd

  4. 68% Ga, 22% In, 10%

  5. 50% Sn, 50% Zn
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Field's metal, or Field's alloy is a fusible alloy that becomes liquid at approximately 62oC. It has 51% In, 32.5% Bi and 16.5% Sn.

Multiple choice

Which of the following statements are false?

  1. 18-carot gold consists of Au 58%, Cu 12–28% and Ag 4–30%.
  2. Sterling-S alloy contains Ag 82.5% and Cu 17.5%.
  3. Naval brass is composed of Cu 60%, Zn 39.25% and Sn 0.75%.
  4. Dow’s metal consists of 93.8% Mg, 6% Al and 0.2% Mn.

  1. 1 and 2

  2. 2 and 3

  3. 3 and 4

  4. 1, 2 and 3

  5. 2, 3 and 4
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
  1. 18-carot gold contains Au 75%, Ag 10–20% and Cu 5–15%. Gold 14-carot consists of Au 58%, Cu 12–28% and Ag 4–30%.
    1. Sterling-S (sterling silver) alloy is composed of Ag 92.5% and Cu 7.5%.
    2. The composition of Naval brass is Cu 60%, Zn 39.25% and Sn 0.75%.4. Dow’s metal is composed of 93.8% Mg, 6% Al and 0.2% Mn. Hence, both 1 and 2 are false.
Multiple choice

Linotype metal alloy contains

  1. 88% Cu, 10% Sn, 2% Zn and 0.5% Pb

  2. 86% Pb, 11% Sb and 3% Sn

  3. 50% Bi, 25% Pb and 25% Sn

  4. 76% Sn and 24% Pb

  5. Cu 25-30%, Zn 25-30% and Ni 40–50%
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Linotype metal alloy contains 86% Pb, 11% Sb and 3% Sn and has been used for over five centuries in printing processes.