Which of the following statements is correct about volatile liquids? They have

Analyze the question: It asks which property describes volatile liquids.

Concept: A volatile liquid is one that evaporates easily at normal temperatures. This happens because its molecules are held together by weak intermolecular forces, so they escape from the liquid surface into the vapour phase with little energy. Examples are ether, petrol, alcohol, and acetone.

Consequences of weak intermolecular forces:

• Low boiling point: little energy is needed to overcome the attractions between molecules.
• High evaporation rate: molecules escape quickly.
• High vapour pressure at a given temperature.
• Usually low viscosity and low density, since the molecules are not strongly attracted to one another.

Checking each option:

• A. Low boiling point: Correct. Weak forces between molecules mean the liquid boils easily.
• B. Low evaporating rate: Wrong. Volatile liquids evaporate fast, so the rate is high.
• C. High conductivity: Wrong. Volatile liquids such as ether and alcohol are poor conductors, and volatility has no connection to conductivity.
• D. High density: Wrong. Many volatile liquids, such as ether and petrol, are less dense than water.
• E. High viscosity: Wrong. Volatile liquids flow easily, so their viscosity is low. Thick liquids like glycerol or engine oil are not volatile.

Answer: A. Volatile liquids have a low boiling point.

Exam tip: Remember "Volatile = Vanishes quickly." A liquid that vanishes (evaporates) fast has a low boiling point, a high evaporation rate, and weak intermolecular forces. Any option claiming the opposite is wrong.