Science Buddies: "Ask an Expert"

Hello! My son is trying the "How Salty is the Sea" project, and we are now conducting the experiment. We chose 5 water samples, and we put them in the larger baby food jars. They are in the oven at 220 degrees as we speak. The experiment states that it takes a few hours to evaporate... 2.5 hrs have passed and the water levels haven't decreased at all! Am I missing something? Thanks!

Hi Superlaura,

Wecome to Science Buddies!

I think you are doing this excellent analytical project from the Science Buddies website.

https://www.sciencebuddies.org/science- ... #procedure

It’s been almost a day since you posted, so hopefully by now, the water has evaporated from all of the jars. In this experiment, there are two options for evaporating the water from the jars, at ambient temperature for several weeks, or in an oven at low heat for several hours. The evaporation rate would depend on a number of factors, including the initial temperature, surface area, and relative humidity, but would take time.

I am interested in know what happened. What size canning jars did you use, and how long did it take for all of the water to evaporate?

Donna Hardy

Having the same problem. 9 hours and the water level has only gone down 1 inch. The oven was at 200 before we put them in AND we only used 8 oz instead of 12 oz jars for fear of this issue. The description of that science experiment needs to be changed to days not hours!

Welcome to Science Buddies!

I will ask the moderator to move your comment to a new topic so you can have your own space.

I apologize that you had a problem with the project directions. I will report the problem to so the directions can be reviewed and corrected. Thank-you so much for taking the time to post your comments.

Other than taking too long, were you able to complete the experiment and get data to use for the project report? Please let us know if you have any questions.


Donna