Question

Because of hydrogen bonds between water molecules, it takes a significant amount of heat energy to make water change temperature. The amount of heat needed to make water change temperature by one degree Celsius is known as the specific heat. This number is much larger for water than it is for most other substances. It also takes a large amount of heat energy to change water from a liquid to a gas. This energy is known as the heat of vaporization. Put a drop of water and a drop of rubbing alcohol on a piece of wax paper. Which drop evaporates first? Explain your results. Make sure that you discuss the role of hydrogen bonds in your results.

Answer 1

The drop of rubbing alcohol will evaporate first.

Step-by-step explanation:

According to the question, HEAT OF VAPORIZATION is the amount of heat energy it takes to change a substance from its liquid state to its gaseous state. Water, as a substance, requires a high amount of this heat of vaporization for its evaporation to occur.

This property is attributed to the HYDROGEN BONDING that forms between water molecules. It takes a high amount of heat energy (heat of vaporization) to break this bond. The hydrogen bonds holds liquid water molecules tightly to one another.

Hence, a drop of water will evaporate slower than a drop of rubbing alcohol, which has a weaker hydrogen bonding between its molecules.