Why does our palm feel cold when acetone or petrol is poured on it?

The correct option is "The liquid absorbs heat from the skin to evaporate".

When liquids like acetone or petrol are poured onto our palm, we experience a cold sensation. This phenomenon is a direct consequence of the process of evaporation and the transfer of thermal energy.

Acetone and petrol are highly volatile liquids, meaning they have low boiling points and evaporate very quickly at room temperature. For any liquid to transition from the liquid state to the gaseous state (evaporate), it requires energy. This energy is known as the latent heat of vaporization.

When these volatile liquids are placed on the skin, they absorb the required latent heat of vaporization directly from our palm. As a result, the temperature of our palm locally decreases due to this loss of thermal energy. This drop in temperature is detected by the thermoreceptors in our skin, making our palm feel cold.