Randy Holmes-Farley
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Reef Chemistry Question of the Day #45 : Brain Teaser
Today we’ll start the week with a question that I’ll call a brain teaser. It requires deeper thinking than most of the typical questions, and for that reason, if the answer does not come to mind without help, feel free to look up things that you think might be useful. It is not as if it is exceptionally advanced chemistry, and does not require measurement data of any sort, it’s just a question that involves thinking through several different processes to come to the answer.
So, you are a mad scientist, or at least you play one at home. You set up an experiment with some left over reef supplies where you take a salt bucket and place 4 glass jars flat on the bottom. Each jar has an internal volume of 500 mL. To each jar you add:
Jar 1. 100 mL of RO/DI water
Jar 2. 100 mL of RO/DI water plus 0.1 g (1.7 millimoles) of anhydrous sodium chloride
Jar 3. 100 mL of RO/DI water plus 0.1 g (1.1 millimoles) of anhydrous magnesium chloride
Jar 4. 100 mL of RO/DI water plus 0.1 g (0.83 millimoles) of anhydrous magnesium sulfate
After adding the ingredients, you seal the salt bucket and leave it in a constant temperature room. After a few years, you decide the experiment is complete, and you come back, open it up, and look inside.
What do you see?
The possible answers are:
A. There is no apparent change, and the relative volumes in jars 1, 2, 3, and 4 is 1 : 1 : 1 : 1
B. There is no water left in any jar, and just dried salts in Jars 2,3,4.
C. Jar 1 is empty, and the relative volumes in jars 2, 3, and 4 is 1 : 1 : 1
D. Jar 1 is empty, and the relative volumes in jars 2, 3, and 4 is 1 : 0.65 : 0.49
E. Jar 1 is empty, and the relative volumes in jars 2, 3, and 4 is 1: 0.97 : 0.49
F. Jar 1 is empty, and the relative volumes in jars 2, 3, and 4 is 1 : 1.5 : 1
G. Jar 1 is empty, and the relative volumes in jars 2, 3, and 4 is 1 : 2 : 2
H. Jars 1, 2 and 3 are empty (except dried salts in some), and all of the fluid is in jar 4
I. Jars 1, 2 and 4 are empty (except dried salts in some) , and all of the fluid is in jar 3
J. Jars 1, 3 and 4 are empty (except dried salts in some), and all of the fluid is in jar 2
K. Jars 2, 3 and 4 are empty (except dried salts in some) , and all of the fluid is in jar 1
L. Something different (what?)
For purposes of this question, assume the salt solutions are “ideal” and the answer does not involve any measurement data that is not supplied. Assume no gas exchange out of or into the sealed bucket. Assume that the system has reached equilibrium.
Good luck!
.
Today we’ll start the week with a question that I’ll call a brain teaser. It requires deeper thinking than most of the typical questions, and for that reason, if the answer does not come to mind without help, feel free to look up things that you think might be useful. It is not as if it is exceptionally advanced chemistry, and does not require measurement data of any sort, it’s just a question that involves thinking through several different processes to come to the answer.
So, you are a mad scientist, or at least you play one at home. You set up an experiment with some left over reef supplies where you take a salt bucket and place 4 glass jars flat on the bottom. Each jar has an internal volume of 500 mL. To each jar you add:
Jar 1. 100 mL of RO/DI water
Jar 2. 100 mL of RO/DI water plus 0.1 g (1.7 millimoles) of anhydrous sodium chloride
Jar 3. 100 mL of RO/DI water plus 0.1 g (1.1 millimoles) of anhydrous magnesium chloride
Jar 4. 100 mL of RO/DI water plus 0.1 g (0.83 millimoles) of anhydrous magnesium sulfate
After adding the ingredients, you seal the salt bucket and leave it in a constant temperature room. After a few years, you decide the experiment is complete, and you come back, open it up, and look inside.
What do you see?
The possible answers are:
A. There is no apparent change, and the relative volumes in jars 1, 2, 3, and 4 is 1 : 1 : 1 : 1
B. There is no water left in any jar, and just dried salts in Jars 2,3,4.
C. Jar 1 is empty, and the relative volumes in jars 2, 3, and 4 is 1 : 1 : 1
D. Jar 1 is empty, and the relative volumes in jars 2, 3, and 4 is 1 : 0.65 : 0.49
E. Jar 1 is empty, and the relative volumes in jars 2, 3, and 4 is 1: 0.97 : 0.49
F. Jar 1 is empty, and the relative volumes in jars 2, 3, and 4 is 1 : 1.5 : 1
G. Jar 1 is empty, and the relative volumes in jars 2, 3, and 4 is 1 : 2 : 2
H. Jars 1, 2 and 3 are empty (except dried salts in some), and all of the fluid is in jar 4
I. Jars 1, 2 and 4 are empty (except dried salts in some) , and all of the fluid is in jar 3
J. Jars 1, 3 and 4 are empty (except dried salts in some), and all of the fluid is in jar 2
K. Jars 2, 3 and 4 are empty (except dried salts in some) , and all of the fluid is in jar 1
L. Something different (what?)
For purposes of this question, assume the salt solutions are “ideal” and the answer does not involve any measurement data that is not supplied. Assume no gas exchange out of or into the sealed bucket. Assume that the system has reached equilibrium.
Good luck!
.
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