Science Buddies: "Ask an Expert"

Question 1: We dissolved 1 cup salt into 4 cups water for a stock solution. Therefore, we called it 20% salt concentration, and dilute it in 1/2 and called that 10% salt concentration. I do not understand why science buddies has called the stock solution 100% and diluted in have%50%.

Question 2: We found egg #4 to float in 109.5 gram of salt per .946 liters of water( or our 7.5% salt concentration)
Now what? How do we prove that the density of that egg is less than the density of that salt water?

Question 3:What kind of graphs or charts can be made with this?

Qestion 4: It seems that after doing the fun experiement of seeing what egg floats in what cup of salt concentration, that you still need to calculate the density of each egg, and you need to calculate the density of the water/salt concentration that floats the egg. How do you calculate the densitly of the salt water?
Help!!!

Hello,

As you already know know, when you add salt to water, it becomes more dense. Eventually, an egg would be able to float when its density is less than the solution.

You will need to do some calculations to determine density of your solution. Here is some background information (read up on buoyancy as it will be helpful).

Here are some links:

http://www.elmhurst.edu/~chm/vchembook/ ... ityfs.html

http://www.chem1.com/acad/webtext/pre/density.html

http://physics.fullerton.edu/~sam/PDF/L ... b%20E3.pdf

http://tlc.ousd.k12.ca.us/~acody/density1.html

http://www.elmhurst.edu/~chm/demos/eggsdensities.htm

You can find information about egg mass, volume, density (which is just mass divided by volume) online.

I suppose you can make a graph that relates mass of salt added, density, and the point where buoyancy is achieved.

Good luck!