Which statement about drying methods is true?

• A. A fan can speed up drying
• B. Increasing temperature slows drying
• C. A catalyst speeds up drying
• D. A hairdryer slows drying

Answer: (A)

Drying happens as water evaporates from a wet surface, and the rate of evaporation increases when the surrounding air can carry away the water vapor. A fan speeds up drying by moving air over the surface, removing the water vapor as it forms and keeping the evaporation process going faster. Increasing temperature actually makes drying faster because warmer molecules escape more easily and the vapor pressure difference with the air grows. A catalyst speeds up chemical reactions, not the physical process of evaporation. A hairdryer also speeds drying by blowing warm air across the surface, not slowing it. So the statement about a fan speeding up drying is the true one.