Free Ionic and Molecular Crystals MCQs with Answers

• A. their ions are held by weak van der Waals forces
• B. strong electrostatic forces act between oppositely charged ions throughout the lattice
• C. they contain covalent bonds between the ions
• D. the ions are free to move at room temperature

Explanation: Every ion attracts all the oppositely charged ions around it, and a great deal of energy is needed to break this extended three…

• A. the covalent bonds within the molecules are weak
• B. they contain no bonds at all
• C. only weak intermolecular forces have to be overcome on melting
• D. their molecules are very heavy

Explanation: Melting separates molecules from one another, and in a molecular crystal they are held only by dispersion forces or dipole interactions…

• A. Ice
• B. Sodium chloride
• C. Solid carbon dioxide
• D. Diamond

Explanation: In diamond every carbon is covalently bonded to four others in a continuous three dimensional network, so melting it means breaking…

• A. melting converts the ions into atoms
• B. the ions become free to move only when the lattice breaks down
• C. electrons are released on melting
• D. the molten salt contains water

Explanation: Conduction in an ionic compound needs mobile charge carriers, and in the solid the ions are locked in fixed lattice positions even though…

• A. their atoms are held in rigid directional covalent bonds
• B. they contain no free electrons
• C. layers of positive ions can slide over one another while the sea of delocalised electrons holds them together
• D. their ions are held by hydrogen bonds

Explanation: Metallic bonding is non directional, so displacing one layer of cations does not break the structure because the delocalised electrons…

• A. Solid iodine
• B. Sodium chloride
• C. Diamond
• D. Copper

Explanation: Iodine molecules are non polar, so the only attraction between them is the temporary induced dipole interaction known as the dispersion…

• A. Ions don't have translatory motion
• B. The coordination number of ion is very high
• C. Free electrons are less
• D. Strong covalent bonds are present in their structure

Explanation: In a solid ionic crystal, positive and negative ions are fixed at lattice positions, so they cannot move through the solid to carry…

• A. Basic salt
• B. Acidic salt
• C. Neutral salt
• D. Amphoteric salt

Explanation: A salt is called acidic when its aqueous solution has pH less than 7, usually because it contains a conjugate acid or a cation that…

• A. 4
• B. 2
• C. 3
• D. 5

Explanation: The formula [Pt(NH3)]Cl2 represents one complex ion and two chloride ions when it dissociates, giving 1 + 2 = 3 ions in solution.

• A. Sharing of electrons
• B. Transfer of electrons
• C. Losing of electrons
• D. Gain of electrons

Explanation: An ionic bond forms when electrons are transferred from one atom to another, producing oppositely charged ions that attract each other.

• A. Graphite
• B. Copper
• C. Molten sodium chloride
• D. Mercury

Explanation: Molten sodium chloride contains mobile Na+ and Cl− ions, which carry electric current through the liquid.

• A. Strong covalent bond
• B. Large value of dipole moment
• C. High polarizability
• D. Strong hydrogen bonding

Explanation: Iodine exists as non-polar I2 molecules, but its large electron cloud is easily distorted, producing strong London dispersion forces that…

• A. Covalent halides
• B. Electronegative halides
• C. Polymeric halides
• D. Polymeric hydrides

Explanation: When halogen atoms bridge between atoms of another element, the halide species form extended chains or networks, so they are called…

• A. Nucleus
• B. Neutrons
• C. Electrons
• D. Protons

Explanation: An ionic bond forms when electrons are transferred from one atom to another, producing oppositely charged cations and anions that attract…

• A. Hydrogen Chloride (HCI)
• B. Chlorine (Cl2)
• C. Xenon(Xe)
• D. Sodium Chloride (NaCI)

Explanation: Sodium chloride has a strong three-dimensional ionic lattice in which oppositely charged Na+ and Cl- ions attract each other.

• A. CaF2
• B. NaCl
• C. Glass
• D. Diamond

Explanation: Glass is an amorphous or pseudo-solid: it has rigidity like a solid but lacks the long-range regular arrangement of particles found in…

• A. Ionic crystal
• B. Covalent crystal
• C. Molecular crystal
• D. Any type of crystal

Explanation: Dry ice is solid carbon dioxide, and its individual CO2 molecules remain intact in the solid.

• A. formula unit
• B. empirical formula
• C. molecular formula
• D. formula mass

Explanation: Ionic compounds form extended crystal lattices rather than separate molecules, so they are described by formula units and formula masses.

• A. Neutral
• B. Positively charged
• C. Negatively charged
• D. Amphoteric

Explanation: This complex is overall neutral because it contains a copper ion with a +2 charge balanced by three ethylenediamine ligands, each…

• A. metallic bonding
• B. covalent bonding
• C. ionic bonding
• D. van der waals binding

Explanation: Inert gases, also known as noble gases, are elements in Group 18 of the periodic table.