Crystal Structures | MCQs

Explanation

• NaCl is also known as Sodium Chloride, or common table salt.
• It is a classic example of an ionic compound, where sodium (Na) loses an electron to become a positively charged ion (cation), and chlorine (Cl) gains an electron to become a negatively charged ion (anion).

Explanation

The pair that is not isomorphous is Na₂CO₃, CaCO₃. 

While both compounds have similar chemical formulas.

The difference in ionic radii between sodium and calcium leads to different crystal structures, making them not isomorphous.

Explanation

• Diamond is a crystalline solid that has a sharp melting point.
• Meaning it melts at a specific temperature (around 4000 K) with a minimal range.

Explanation

• Ionic crystals are typically characterized by high melting points due to the strong electrostatic forces between the positively and negatively charged ions.
• The attractive forces between oppositely charged ions are strong, requiring a significant amount of energy to overcome, resulting in high melting points.

Explanation

• In a NaCl crystal lattice, each sodium (Na+) ion is surrounded by six chlorine (Cl-) ions, forming an octahedral geometry.
• This means that each Na+ ion is coordinated by six Cl- ions, and vice versa.

Explanation

• At room temperature, most ionic compounds are crystalline solids, meaning they have a rigid and orderly crystal structure.
• This is because the strong electrostatic forces between the oppositely charged ions hold them in a fixed position, creating a three-dimensional lattice.