Answer to Question #334837 in General Chemistry for Zaza

Question

In terms of heat flow, explain briefly:

1) Why silverware feels cold to touch

2) Why you feel cool after alcohol is rubbed on your skin

Answer 1

1. It’s basically because silver conducts heat very well, better than any other metal. If you grab a silver spoon with your bare hands, you usually do it in a room about 20 °C warm - so the spoon is also 20 °C. But your hand is some 35–37 °C warm, so heat will flow from the hand into the spoon. When two temperatures meet, they’ll always try to create an equilibrium, to find a common average. As heat flows from you, you feel it to be colder.
2. The alcohol is very volatile, meaning it evaporates quickly. Going from liquid to vapor requires heat to be added to the alcohol… the heat is extracted from your skin. That causes a local drop in temperature where it evaporates, making you feel cold at that spot.