All Free Chemistry MCQs with Answers

• A. Relieving internal stress
• B. Removing air bubbles
• C. Eliminating impurities
• D. Enhancing surface shine

Explanation: Annealing is a vital process in glass manufacturing aimed at relieving internal stresses that develop during cooling.

• A. Air bubbles
• B. Impurities
• C. Strain
• D. Shining

Explanation: The process of annealing glass is done to reduce internal stresses or strain which could otherwise lead to cracking.

• A. Covalent bonds
• B. Ionic bonds
• C. Metallic bonds
• D. H-bonds

Explanation: Solid mercury, or simply mercury (Hg) in its solid state, is an example of a metal.

• A. Crystal geometry
• B. Crystal lattice
• C. Crystal habit
• D. None of the above

Explanation: The general shape of a crystal and the proportions of its bounding sides-such as elongate, tabular, bladed, or other-is known as its…

• A. Pure C6H22O6
• B. Impure NaCl
• C. Glass
• D. Mixture of the above two

Explanation: Pure substances generally have sharp melting points. When a pure compound like glucose is heated, it undergoes a phase change from solid…

• A. visible
• B. infrated
• C. X rays
• D. ultraviolet

Explanation: To determine the structure of crystalline solids, the spacing between the atoms of crystal (i.e.

• A. Amorphous solids
• B. Glassy solids
• C. Polymers
• D. Crystals

Explanation: Crystals are characterized by a precise and repeating lattice structure that extends in all three spatial dimensions, resulting in a…

• A. Copper and diamond
• B. Copper and glass
• C. Copper and rubber
• D. Diamond and glass

Explanation: Diamond is a crystal that is transparent to opaque and generally isotropic, native copper is a polycrystal. Therefore the answer will be A.

• A. Allotropes
• B. Polymorphous
• C. Isomorphous
• D. None of these

Explanation: Two or more substances having the same crystal structure called isomorphous.

• A. Gemstone
• B. Calcium oxide
• C. Graphite
• D. Diamond

Explanation: When we talk about melting points, we're referring to the temperature at which a substance changes from a solid to a liquid.

• A. Graphite
• B. Nacl crystals
• C. Copper crystals
• D. Ice

Explanation: Graphite has a unique structure made up of layers of carbon atoms arranged in a hexagonal pattern.

• A. Cubic
• B. Orthrombic
• C. Tetragonal
• D. Rhombohedral

Explanation: Option D is correct.The crystal system that does not have β=γ=90° is rhombohedral.

• A. PbCrO4
• B. BaSO4
• C. ZnO
• D. NaOH

Explanation: The correct answer is Barium sulfate (BaSO₄), which crystallizes in the orthorhombic crystal system.

• A. Anisotropy
• B. Isomorphism
• C. Polymorphism
• D. Allotropy

Explanation: Allotropy refers to the ability of an element to exist in different physical forms, often with different crystal structures or molecular…

• A. Cubic
• B. Monoclinic
• C. Orthorhombic
• D. Triclinic

Explanation: In crystallography, the crystal system is determined by the lengths of the axes and the angles between them.

• A. HCl
• B. HF
• C. H2O
• D. CO2

Explanation: CO2 is the correct answer because even though it contains polar bonds between C and O, its linear molecular geometry results in the…

• A. B....Cl
• B. C....Cl
• C. C....I
• D. C....Br

Explanation: CI represents the bond between carbon (C) and iodine (I), which has the least electronegativity, resulting in the least polar bond.

• A. Br
• B. SiF
• C. CaO
• D. SeH2

Explanation: A covalent bond is not likely to exist in CaO. Calcium is a metal, and oxygen is a non-metal.

• A. HF
• B. HI
• C. HCl
• D. HBr

Explanation: To determine the polarity of diatomic molecules, we examine the difference in electronegativity between the two atoms.

• A. Electron mass is 1/87th of proton
• B. Electron are universal particles of all matter
• C. Electrons are produced in discharge
• D. None of the above

Explanation: The constancy of the e/m ratio for electrons despite variations in the gas present in the discharge tube or in the material of the cathode…