Which of the following factors does not affect the rate of evaporation of a liquid?

Analyze the question: We need the factor that does NOT affect how fast a liquid evaporates.

Concept: Evaporation happens at the surface of a liquid, when the faster-moving molecules escape into the air. The rate depends on:

1. Temperature: Higher temperature gives molecules more kinetic energy, so more escape. This affects the rate.
2. Surface area: A larger exposed surface lets more molecules escape at once. This affects the rate.
3. Wind (air movement): Wind carries away vapour molecules above the surface, so fewer return to the liquid. This affects the rate.
4. Humidity: If the air is already moist, evaporation is slower.
5. Nature of the liquid: Volatile liquids like ethanol or petrol evaporate faster than water.

Check each option:

• A. Temperature: affects the rate.
• B. Volume: the amount of liquid does not change how quickly molecules leave the surface. A cup of water and a bucket of water with the same surface area and conditions evaporate at the same rate per unit area. The larger volume simply takes longer to dry up completely. So volume does not affect the rate.
• C. Wind: affects the rate.
• D. Surface area: affects the rate.

Answer: B. Volume.

Tip: Evaporation is a surface phenomenon. If a factor is not about the surface, the molecules' energy, or the air above the surface, it probably doesn't affect the rate. Remember "TASH": Temperature, Area, Surrounding air movement (wind), Humidity.