Which option correctly describes the phase described for acetone as a fuel?

Which option correctly describes the phase described for acetone as a fuel?

• A. Evaporation
• B. Vapor-liquid equilibrium
• C. Condensation
• D. Sublimation

Answer: (D)

Acetone used as a fuel needs to be in vapor form to burn efficiently, so the phase change involved is liquid turning into gas. This is evaporation—molecules at the surface gain enough energy to escape into the vapor phase, which can occur even before the liquid reaches its boiling point. Sublimation would require solid acetone turning directly into gas, which isn’t the typical state for acetone under normal conditions. Condensation is the reverse process (gas to liquid), and vapor–liquid equilibrium describes a situation where both phases are present together, not the actual change from liquid to gas.

Acetone used as a fuel needs to be in vapor form to burn efficiently, so the phase change involved is liquid turning into gas. This is evaporation—molecules at the surface gain enough energy to escape into the vapor phase, which can occur even before the liquid reaches its boiling point. Sublimation would require solid acetone turning directly into gas, which isn’t the typical state for acetone under normal conditions. Condensation is the reverse process (gas to liquid), and vapor–liquid equilibrium describes a situation where both phases are present together, not the actual change from liquid to gas.