All Questions
44
questions
51
votes
9
answers
519k
views
Why does ice water get colder when salt is added?
It is well known that when you add salt to ice, the ice not only melts but will actually get colder. From chemistry books, I've learned that salt will lower the freezing point of water. But I’m a ...
- 627
28
votes
5
answers
17k
views
Why is water "the universal" solvent?
This is an old question that our textbook tried to answer but worsened the situation.
Many things are soluble in water. So many, that studying solutions will always require studying aqueous ones. It ...
- 10.7k
21
votes
3
answers
5k
views
Does freezing a solution with water always cause the water to separate and form the ice lattice?
I'm curious, I was trying to look into the affect of freezing a solution with water even when the solution is completely miscible. I came across something that detailed this regarding salt water and ...
- 293
19
votes
3
answers
60k
views
Why there is no change in water level when salt is added?
Let us say we have one glass of water and after that when we add one or two spoon of salt then we notice that salt dissolves in it but when we measure the water level we found that there is no ...
- 1,491
14
votes
1
answer
521
views
Why do some solutions eventually stop boiling and start "popping" as they get more concentrated?
A very long time ago I performed an experiment in my kitchen, part of which was to remove all water from a solution. Unfortunately I don't remember what was in it, but the point is that as the ...
- 271
12
votes
3
answers
42k
views
How is dissolving a physical change and not a chemical change?
When salt dissolves in water it dissociates and it is no longer in a lattice structure. The electrostatic forces are no longer there and are replaced by water-ion interactions. To me that sounds like ...
- 519
9
votes
2
answers
31k
views
How much does water expand when heated, and does salt affect that?
For this question, assume all things not mentioned are perfectly controlled, all at 14.7lbs of atmospheric pressure, and water is 100% pure of anything not mentioned, with no dissolved air.
Given a ...
- 193
9
votes
1
answer
4k
views
Why does Dead Sea water feel greasy?
The best explanation I found so far is this:
These salts (magnesium, potassium, sodium, etc.) are responsible for the "greasy" feel of the water.
But it doesn’t say which salts exactly are ...
- 201
7
votes
1
answer
2k
views
Why do some solid chemicals dissolve better in colder water?
I just discovered that some solid chemicals, such as $\ce{Na2SO4}$, dissolve better in cold water than hot water from here and would like to know if there is any particular reason as to why. Is it ...
- 173
5
votes
2
answers
3k
views
A solution is cloudy at lower concentration and becomes clear at higher concentration. Why?
This might be just an "everyday life science" question. I am a university professor but not in chemistry so please educate me. Today I was adding some floor cleaner formula to water as ...
- 59
4
votes
1
answer
6k
views
Explain volume contraction in mixtures of alcohol and water
Could someone explain why volume contraction occurs when you mix an alcohol such as ethanol with water in relation hydrogen bonding and the dipole-dipole forces?
- 49
4
votes
1
answer
274
views
Why is Iron very rare in seawater compared to many other elements?
I don't know the associated technical words to research this question.
There was high presence of Iron in the oceans in anoxic precambrian times, and today copper is 5 times more abundant in the ...
- 573
4
votes
1
answer
273
views
Liquid that does not spoil for a mineral aquarium
I want to create a decoration - a mason jar "aquarium". I want to take a large mason jar, put some nice mineral specimens in it, fill the jar with liquid and seal it with lid.
I believe I can't use ...
- 41
4
votes
0
answers
169
views
How do xanthan gum and other hydrocolloids work?
Does anyone know what causes things like xanthan gum to make water into a slimy substance on the molecular level?
- 41
3
votes
1
answer
5k
views
Does NaCl reduce the surface tension of water?
Does NaCl reduce the surface tension of water? And why?
For example soap does it, and I was wondering if NaCl does the same.
- 33