Why does our palm feel cold when we put some acetone or petrol or perfume on it?

When we put substances like acetone, petrol, or perfume on our palm, it feels cold due to a process called evaporation. Here’s why:

1. Evaporation: These substances have low boiling points, which means they evaporate quickly at room temperature. When they come into contact with the warmth of our skin, they begin to evaporate rapidly.
2. Heat Absorption: Evaporation is an endothermic process, meaning it absorbs heat from its surroundings to occur. As the substances evaporate from our palm, they absorb heat energy from our skin and the surrounding air.
3. Heat Transfer: The heat required for evaporation is drawn from the surrounding environment, including our skin. This rapid transfer of heat away from our skin makes it feel cooler.
4. Sensory Perception: Our sensory receptors interpret this rapid heat loss as a sensation of coldness, even though the temperature of the substance itself may not be particularly cold.

In summary, the cooling sensation we feel when we put substances like acetone, petrol, or perfume on our palm is due to the rapid evaporation of these substances, which absorbs heat from our skin and makes it feel cold.