Science Buddies: "Ask an Expert"

Hello! I have to ask an expert a few questions (at least 6) for my science project at school. My topic is on Evaporation of Liquids. My question is Do All Liquids Evaporate At The Same Rate? Here is the questions I have:

1. What is something you (expert) know about evaporation (of liquids, or in general) that might be important for me to know?

2. Have you ever conducted an experiment/study/research project on evaporation? (what experience do you have with evaporation)

3. Why might knowing if all liquids evaporate at the same rate benefit society?

4. Do all liquids evaporate?

5. What would be 3 liquids that may be good to test? (for evaporation rate)

6. What would happen if liquids never evaporated?

I hope the scientists/experts over here at science buddies can help me out! Thanks for looking over my questions.

Dear pdunkle,

Thank you for using the Ask an Expert forums. I hope that my answer is helpful, but leaves some questions for you to answer. I don't want to do your project for you, after all!

1. As an Expert, I know that the process of evaporation occurs when a substance in the liquid state changes state to a gas. Evaporation usually results from the addition of heat energy to the substance. As you probably know, the molecules in a liquid are close enough to be a visible substance, but loose enough to have very little shape. As heat energy is applied, the molecules of the liquid become excited and move faster. They also spread apart. Such are the properties of molecules in a gas. Additionally, I recall that the rate of evaporation is affected by pressure. Water boils more quickly in thinner air. Lastly, I know that while a substance is changing states, (i.e., melting, evaporating, freezing, condensing, etc.) its temperature remains constant.

2. I have not done a real experiment on evaporation. The closest I have come was a class demonstration of rain in second grade. However, having taken matter and energy and earth science as part of my requirements for graduating middle school, I understand the states of matter and the water cycle.

3. This question in particular sounds like it should be answered by the investigator. I would say that knowing the evaporation rate of certain substances might help in some processes such as distilling beer. However, this would be a good place to start your research.

4. Excellent question. I believe that all liquids can evaporate. On the contrary, not all solids can melt. Solid carbon dioxide, for example, is called 'dry ice' because it does not melt. Instead, it changes states from a solid directly to a gas. This process is known as deposition.

5. Three liquids that would be good to test are: Water, (you need a control group) alcohol, (this is sometimes evaporated for experiments) and a third substance. I would suggest honey, because I have no idea how honey evaporates. Of course, these are only suggestions. You really should test water in order to form a basis for comparison, though. The other liquids could really be anything. Oil could work, too.

6. This is another good question. If water never evaporated, there would be no rain because rain clouds could never form. If there was no rain, there would likely be no water on large masses of land, outside of lakes. I'm not sure if lakes would have ever formed. I think they could form without evaporation as a result of tectonic activity around an underground river. Without much water on large land masses, life would be almost completely aquatic and confined to the oceans. In other words, you'd be a seal. Arp.

I hope this helps. Let me know if you have any other questions or if any of these answers require clarification.

Good luck with your Science Fair!

- Ultra

This will help tons with my report/project! Thank you so much for taking your time to answer my questions!!

I would add that indeed all liquids can evaporate. Evaporation itself is just the moment that your molecules go through a phase change from liquid to gas. However, the speed at which something evaporates is completely different. That is contingent upon density and temperature (as well as the obvious--how much of a given liquid you have). For instance vodka evaporates at a much lower temperature than apple juice.

Great project!! Enjoy!!

what is the scientific method on the question....do all liquids evaporate at the same rate

Instead, it changes states from a solid directly to a gas. This process is known as deposition.

Hello Ultra,

I quoted what you said but the process from solid to gas is not deposition it is sublimation.

Good call, XtremeScience!

Either my source was incorrect, or I misread it. Deposition is the transition of a gas to a solid. Sublimation is the transition of a solid to a gas.

I apologize for any inconvenience.

Happy science,

- Ultra

Hi, Ultra can you give me your email if you have one???? I have 6 questions that I was hoping you can answer about evaporation. It's for my science project at school. I am doing my project on " do all liquids evaporate at the same rate"? I was hoping to get professional advise from you so I can get full credit..... So if you can get back to me as soon as possible I would really appreciate it!!!!

_kaiden03,

I am sorry, but for security reasons, Science Buddies experts are not allowed to share contact information.

Feel free to post your six questions here, instead.

I apologize for the inconvenience.
- Ultra

1) What is something you (expert) know about evaporation ( of liquids, or In general) that might be important for me to know???

2) Have you ever conducted an experiment/ study/ research projects on evaporation? ( What experierence do you have with evaporation??

3) Why might knowing if all liquids evaporate at the same rate Benefit society??

4) Do all liquids evaporate????

5) What would be three liquids that may be good to test?? ( For evaporation rate)

6) What would happen if liquids never evaporated????

If you have the time can you please answer the question because I need these answers by tomorrow!!!!!! Not to sound demanding But I was really hoping they would be answered by tonight so I have time to write your answer in!!!! Thank you so much!!!!!!!

~ _kaiden03