Chemistry MCQs
Chemistry Objective (Multiple Choice) General Knowledge Questions & Answers for SSC-CGL, UPPSC, UPSC, NDA, CDS and UPSC Civil Services Prelims Examination.
1. Which among the following kinds of glass is used generally in making of the Bullet proof screens?
[A] Pyrex glass
[B] Jena glass
[C] Reinforced Glass
[D] Flint Glass
Show Answer
Correct Answer: C [Reinforced Glass]
Notes:
Reinforced Glass or Toughened glass or tempered glass is a kind of safety glass is used as s a component of bulletproof glass, for diving masks, and various types of plates and cookware.
2. Which gas is produced when an alkali metal, like Lithium or Sodium, reacts with water?
[A] Oxygen
[B] Hydrogen
[C] Ozone
[D] Carbon Dioxide
Show Answer
Correct Answer: B [Hydrogen]
Notes:
The reaction of alkali metals with water produces Hydrogen gas. These metals are part of the first group on the period table and include lithium, sodium, and potassium. They are known for their vigorous reactions with water, which results in the liberation of hydrogen gas. Along with the gas, this reaction also forms a basic alkali metal hydroxide, which gives the solution its characteristic basic or alkaline properties.
3. Which among the following groups is characteristic to alcohols?
[A] OH group
[B] COOH group
[C] COO group
[D] CO group
Show Answer
Correct Answer: A [OH group]
Notes:
Alcohols are organic compounds characterized by the presence of a hydroxyl group, denoted as -OH. This group consists of one oxygen atom bonded to a hydrogen atom. Due to the presence of the hydroxyl group, alcohols exhibit unique properties, such as the ability to form hydrogen bonds, making them polar. Alcohols are distinct from carboxylic acids (COOH), carbonates (COO), and carbonyl group compounds (CO).
4. Which among the following is the property of Tungsten which makes it eligible to use in the bulbs?
[A] highest melting point
[B] highest resistance
[C] Highest malleability
[D] All are correct
Show Answer
Correct Answer: A [highest melting point]
Notes:
The electric heating is also used to produce light, as in an electric bulb. Here, the filament must retain as much of the heat generated as is possible, so that it gets very hot and emits light. It must not melt at such high temperature. A strong metal with high melting point such as tungsten (melting point 3380°C) is used for making bulb filaments. The filament should be thermally isolated as much as possible, using insulating support, etc. The bulbs are usually filled with chemically inactive nitrogen and argon gases to prolong the life of filament. Most of the power consumed by the filament appears as heat, but a small part of it is in the form of light radiated.
5. Which among the following is an ionic solid?
[A] Diamond
[B] Dry ice
[C] Table salt
[D] All are ionic solids
Show Answer
Correct Answer: C [Table salt]
Notes:
One important character of Ionic solids is that they readily get dissolved in water
6. Cassiterite is a primary ore of which of the following elements?
[A] Iron
[B] Zinc
[C] Copper
[D] Tin
Show Answer
Correct Answer: D [Tin]
Notes:
Cassiterite is a mineral that is a significant ore of tin. It is also known as tin oxide. Although rare, its key characteristic is its high specific gravity that makes it easy to separate it from other materials. Tin, which is extracted from Cassiterite, is commonly used in making alloys, punches, and cutting tools.
7. Which among the following allotropes of Oxygen is found in 6 phases under various pressures and temperatures?
[A] Ozone
[B] Tetra oxygen
[C] Octaoxygen
[D] None of them
Show Answer
Correct Answer: C [Octaoxygen]
Notes:
The correct answer is Octaoxygen. Octaoxygen (O8) is an allotrope of oxygen that can exist in multiple phases under varying pressures and temperatures. It was first synthesized in 2001 and is notable for its unique molecular structure, which consists of eight oxygen atoms. Ozone (O3) is well-known but does not exhibit multiple phases like octaoxygen. Tetraoxygen (O4) is less stable and not commonly referenced in the same context.
8. Which among the following is Fool’s Gold?
[A] Copper Sulphate
[B] Iron Sulfide
[C] Brass
[D] Silver Bromide
Show Answer
Correct Answer: B [Iron Sulfide]
Notes:
The mineral pyrite or iron pyrite, also known as fool’s gold, is an iron sulfide with the chemical formula FeS2 (iron (II) disulfide). “Fool’s Gold” is technically known as pyrite or iron sulfide (FeS2) and is one of the most common sulfide minerals. Its nickname is “Fool’s Gold,” but it often contains a surprising amount of gold.
9. The synthetic rubber Buna is obtained from the reaction of an unsaturated hydrocarbon with ___:
[A] Sodium
[B] Magnesium
[C] Potassium
[D] Lithium
Show Answer
Correct Answer: A [Sodium]
Notes:
Buna-S is a synthetic rubber formed by co-polymerization of a mixture of 1:3 butadiene and styrene. It is obtained from Sodium.
10. Ground Level Ozone is formed due to reaction between:
[A] VOCs, Oxides of Nitrogen & Sunlight
[B] VOCs, Sulphur dioxide & Sunlight
[C] Ozone, Sulphur dioxide & Oxides of Nitrogen
[D] Ozone, Oxides of Nitrogen & Sunlight
Show Answer
Correct Answer: A [VOCs, Oxides of Nitrogen & Sunlight]
Notes:
Ground Level Ozone results from photochemical reactions between oxides of nitrogen (NOx) and volatile organic compounds (VOCs) in the presence of sunlight.