Chapter 17, Problem 5TE

To determine

The smell of alcohol when cotton ball dipped in alcohol is rubbed on table top which is warmer.

Answer to Problem 5TE

Smell of alcohol will be more evident when then surface of table top is warmer.

Explanation of Solution

Alcohol is a very volatile liquid i.e.; it changes its state from liquid to vapour very fast due to its very low boiling point.

Evaporation is the phenomenon of vaporisation of liquid at temperature below the boiling point. Its rate can be increased by various factors like large surface area, high wind speed, low humidity and high temperature.

When alcohol is rubbed on table top, we are basically spreading it causing its surface area to increase, when the surface area is large the number of molecules in contact with atmosphere are more, hence number of molecules evaporating increases.

If the temperature of table top is higher the rate of evaporation will increase because the energy supplied to the molecules in form of heat will increase the kinetic energy of molecules causing them to move faster after evaporation and hence making the smell of alcohol more evident.

Conclusion:

Therefore, smell of alcohol will be more noticeable if the table is warmer.