is it true that ethanol on skin feels cold due to the evaporation of the alcohol
yes. But any solvent with a decent vapor pressure will do the same thing. Even water but you may need to wave your hands in the air to help it a little. That's why humans perspire; that is, they get hot, the body needs cooling, we perspire, the sweat evaporates, the body cools. Back to normal T.
Yes, it is true that ethanol on the skin can feel cold due to the evaporation of the alcohol. When you apply ethanol to your skin, it quickly starts evaporating into the air. During this process, the molecules of ethanol gain enough energy to escape from the liquid and become vapor. As ethanol molecules leave the surface of your skin, they take away some of the heat energy with them, causing the surrounding area to feel cooler.
This phenomenon is known as evaporative cooling. When a liquid evaporates, it absorbs heat from its surroundings, resulting in a decrease in temperature. Ethanol has a relatively high vapor pressure, which means it evaporates fairly quickly. As a result, when it comes into contact with your skin, it rapidly evaporates and causes a cooling sensation.
It's worth noting that this cooling effect isn't unique to ethanol. Any solvent with a decent vapor pressure, such as acetone or rubbing alcohol, can produce a similar cooling sensation when applied to the skin. Even water can create a cooling effect, although it may require additional assistance like waving your hands in the air to aid evaporation.
In summary, when you apply ethanol to your skin, its evaporation leads to a cooling sensation due to the removal of heat energy. This effect is a result of the evaporative cooling phenomenon that occurs when a liquid transforms into a vapor.