Covalent molecular

Covalent molecular

Overview:

• Covalent molecular compounds are formed when atoms share electrons to create discrete molecules held together by covalent bonds.
• These compounds have distinct properties that are different from ionic and covalent network compounds.

Low Melting and Boiling Points:

• Covalent molecular compounds typically have low melting and boiling points.
• This is because the intermolecular forces between the molecules, while relatively weak, are enough to hold them together in a solid or liquid state at lower temperatures.

Non-Conductors of Electricity:

• Covalent molecular compounds do not conduct electricity in either the solid or liquid state.
• They lack free-moving ions or electrons that are necessary for electrical conductivity.

Variation in Properties:

• Similar molecular formulas can result in different properties due to the presence or absence of specific intermolecular bonds.
• For example, ethanol and ether both have the molecular formula C₂H₆O but differ significantly in boiling points.

Example: Ethanol vs. Ether:

• Ethanol (C₂H₅OH) has a boiling point of 79°C and is a liquid at room temperature.
• Ether (CH₃OCH₃) has a boiling point of -23°C and is a gas at room temperature.
• The difference in boiling points is due to the presence of hydrogen bonding in ethanol, which is absent in ether.

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Covalent molecular

Hydrogen Bonding:

• Some covalent molecular compounds exhibit higher melting and boiling points than expected due to the presence of hydrogen bonding.
• For example, ammonia (NH₃) and hydrogen fluoride (HF) have higher boiling points because of hydrogen bonding between their molecules.

Importance:

• Understanding covalent molecular compounds and their properties is crucial in chemistry, as they make up a vast array of substances found in everyday life, including organic molecules, pharmaceuticals, and more.