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Equation # 1
p= m/v for us p= m-292 grams of salt over v- .946 liters of water Basically- 1 cup of salt in 1 quart of water- STOCK
p= 309 or 308.6 = Is this grams per mililiter? Is this the density of the salty water- our stock-?
Next, Equation # 2
new concentration - Volume of stock/(volume of stock + volume of water)
Cups
#1- 3/4 cup stock
#2- 3/4 cup stock & 3/4 cup water- new mix 50% or 1/2 stock
#3- 3/4 cup water & new mix 3/4 cup stock from #2 - 25% or 1/4 stock
#4- 3/4 cup water & new mix 3/4 cup stock from #3 - 12.5% or 1/8 stock
#5- 3/4 water
so, do we divide the 309 by 2, 4 , and 8 for the densities-absolute solutions- for cups 2-4??????????
Is the relative solutions the percentages?????????
Please Help??????? Project due tomorrow!
How Salty does the Sea have to be for an egg to float?
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OrtizR
- Posts: 1
- Joined: Mon Oct 08, 2012 9:36 am
- Occupation: Student
- Project Question: Egg float! equation 1 we put Mass as 292 grams of salt. We put Volume as .946 for water. We got P- or density as 308.6 o6 309. in liters or grams or grams per liter. Now to figure out the Volume of stock. Is 309 the volume of stock? If so, them for relative solution we have 1 for cup 1, 50% for cup 2, 25% for cup 3, and 12.5% for cup 4. Then absolute solution will be 309 divided by 2 for cup 2(1/2), 4 for cup 3(1/4), and 8 for cup 4(1/8).
- Project Due Date: 10-8-12
- Project Status: I am finished with my experiment and analyzing the data
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klhjbh62604
- Posts: 22
- Joined: Thu Sep 06, 2012 9:37 am
- Occupation: Scientist
- Project Question: Ask the Expert Volunteer.
- Project Due Date: n/a
- Project Status: Not applicable
Re: How Salty does the Sea have to be for an egg to float?
Hello OrtizR:
It looks like you are well on your way to understanding this experiment.
I would like you to take a look at the units you are using for equation #1. As you have stated the your mass is in grams and your volume is in liters. Therefore, with p=m/v your units would be grams per liter. As p represents the density, this is the density of your stock.
Please let me know if you have any follow-up questions.
Kati
It looks like you are well on your way to understanding this experiment.
I would like you to take a look at the units you are using for equation #1. As you have stated the your mass is in grams and your volume is in liters. Therefore, with p=m/v your units would be grams per liter. As p represents the density, this is the density of your stock.
Please let me know if you have any follow-up questions.
Kati
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rababm
- Posts: 1
- Joined: Fri Apr 01, 2016 10:44 am
- Occupation: Teacher
Re: How Salty does the Sea have to be for an egg to float?
Hello,
I am a parent/teacher helping a student with this experiment.
I read your response to the calculation of density of the stock solution and how to figure out the density of the other concentrations.
It doesn't make sense that the density of the stock which should be 292g of salt in 1183 mL of water (5 cups) will be 292/1183= .246g/mL. If that's the density of the stock solution, it's less than the density of water. The density of the stock should be greater than the density of water because the egg floats in the stock but not the water. Are we supposed to factor in the density of water into this? How do we do that?
How do I explain to the student that the egg will not float in water because it's density is more than the density of water which is 1g/mL but it floats in a solution with less density???
please help!!!
Also, once we find the density of the stock solution, we can find the rest of the cups by taking percentages like 50%, then 25%, then 12.5%?
than you!!
I am a parent/teacher helping a student with this experiment.
I read your response to the calculation of density of the stock solution and how to figure out the density of the other concentrations.
It doesn't make sense that the density of the stock which should be 292g of salt in 1183 mL of water (5 cups) will be 292/1183= .246g/mL. If that's the density of the stock solution, it's less than the density of water. The density of the stock should be greater than the density of water because the egg floats in the stock but not the water. Are we supposed to factor in the density of water into this? How do we do that?
How do I explain to the student that the egg will not float in water because it's density is more than the density of water which is 1g/mL but it floats in a solution with less density???
please help!!!
Also, once we find the density of the stock solution, we can find the rest of the cups by taking percentages like 50%, then 25%, then 12.5%?
than you!!
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SciB
- Expert
- Posts: 2071
- Joined: Fri Feb 01, 2013 7:00 am
- Occupation: Retired molecular biologist, university researcher and teacher
- Project Question: I wish to join Scibuddies to be able to help students achieve the best science project possible and to understand the science behind it.
- Project Due Date: n/a
- Project Status: Not applicable
Re: How Salty does the Sea have to be for an egg to float?
Hi,
Sorry for the confusion about densities. You have to add in the weight of the water when calculating density.
One milliliter of water at 21 C weighs about 1.00 grams. When you add 292 g of NaCl to 1183 ml of water (about 24%) the total volume is increased somewhat and you have a solution with a density between 1.18 and 1.19 g/ml.
I did a search for density of sodium chloride solutions and found a number of sites listing different concentrations of NaCl and the corresponding density. Here's an example: https://www.google.com/url?sa=t&rct=j&q ... m8SHBBIQ0w
Don't be confused by some of the density values because they are given in kilograms per cubic meter. Just divide the value by 1000 to convert it to grams per cubic centimeter, g/ml.
I hope this helps.
Sybee
Sorry for the confusion about densities. You have to add in the weight of the water when calculating density.
One milliliter of water at 21 C weighs about 1.00 grams. When you add 292 g of NaCl to 1183 ml of water (about 24%) the total volume is increased somewhat and you have a solution with a density between 1.18 and 1.19 g/ml.
I did a search for density of sodium chloride solutions and found a number of sites listing different concentrations of NaCl and the corresponding density. Here's an example: https://www.google.com/url?sa=t&rct=j&q ... m8SHBBIQ0w
Don't be confused by some of the density values because they are given in kilograms per cubic meter. Just divide the value by 1000 to convert it to grams per cubic centimeter, g/ml.
I hope this helps.
Sybee