For questions relating to water (H2O), specifically its structure, properties, and uses in chemistry.

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4
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0answers
57 views

What stable arrangements of hydrogen-bonded water exist in the range of 4-20 water molecules?

Water clusters made up of various numbers of water molecules have been described. Are all of these structures theoretical? What experimental evidence supports any of these structures? How does the ...
2
votes
1answer
14 views

High/low density water solution values

I would like to know what min and max values of densities are achievable with water solutions. There are some conditions: 1. Normal or close to normal temperature; 2. Non-radioactive ...
3
votes
2answers
50 views

How can the density of water be maximised?

What is the maximum possible density of water at room temperature? The density of the water in the dead sea at 37 Celsius is 1.24. Would it be possible to increase density as such using salts we add ...
3
votes
1answer
37 views

Ethanol and water hygroscopic equilibrium concentration

I am working with a company to help improve their reaction process where they use SDA 2B Alcohol (Karl Fischer titration has it at 99.66% EtOH, 0.3375% toluene). Specifically, I am attempting to ...
1
vote
1answer
19 views

Can electrolyzing ice cause an explosion?

I know electrolyzing water separates it into hydrogen and oxygen. However, I am curious, if ice is electrolyzed, could it explode? My thought process is that oxygen and hydrogen bubbles would build ...
1
vote
1answer
41 views

Can water be produced by mixing hydrogen gas and oxygen?

Could there be some kind of process, a kind of "retrograde electrolysis" where hydrogen gas (or in some other form) and oxygen gas (or in some there form) are mixed with required energy to combine to ...
2
votes
1answer
67 views

Is there a readily available liquid that's more dense than water and insoluble?

I am looking for any liquid that does not dissolve in water with higher density and does not react with water, one that is readily available.
6
votes
1answer
260 views

Soap and rain water, why does it not rinse off?

I am in Papua New Guinea at the moment, where rain water harvesting is the most common way of getting water. When washing hands, the soap feels hard to rinse off, and my skin feels "greasy". I read ...
1
vote
0answers
15 views

What is electrodialysis and is electrolysis prevented or suppressed?

Recently, I was introduced to a method of desalinization called electrodialysis in which a current was applied to salt water in such a way that the positive and negative were separated and drawn ...
1
vote
1answer
26 views

Which acids are created by the combination of a gas and water?

Which acids are created by the combination of a gas and water? I know that carbonic acid is created by combining carbon dioxide and water, but are there others? Is there a specific name for this ...
0
votes
1answer
35 views

Solar still and how it works

I use a solar still that holds 182 cubic feet of water. Here is how it works: There is an insulator on both sides of the metal bowl. On the outside it covers the whole thing. on the inside it covers ...
0
votes
1answer
42 views

What are the methods of fluoride removal from drinking water?

I would like to remove fluoride from my water supply. Are there any methods, any test kits or water distillation units to remove fluoride from drinking water? See also: Is there any at home test ...
0
votes
1answer
20 views

How to test for fluoride levels in drinking water?

I would like to test for fluoride levels in the water. Are there any methods or test kits available to test the levels of fluoride in home water supply? See also: Is there any at home test for ...
3
votes
0answers
49 views

Rusting of an Iron Nail in Oil and Water

Recently at school, I did some experiments on corrosion. Everything mostly went as expected, but the result in one of the test was quite baffling. This test had an iron nail in water with some of the ...
1
vote
0answers
31 views

How to determine amount of CO₂ in soda water

I've got a problem in determining the amount of $\ce{CO2}$ in soda water. Basically, I have boiled some purified water to remove the dissolved gas. By using a SodaStream machine, I made carbonated ...
0
votes
1answer
26 views

Can I perform electrolysis without electrolyte? (with distilled water)

When performing electrolysis at home, I usually used salt water as electrolyte. The problem is, that this method also produces chlorine and chlorine is aggressive to both humans and electrical ...
1
vote
1answer
19 views

Double Deionized Water and Superheating

I was told that dd-water will superheat when heated up in a microwave because of a lack of ions. 1) Doesn't water auto-ionize? I asked this; the answer was it auto-ionizes "too slowly" in dd-water ...
3
votes
2answers
61 views

What is the reason for anomalous expansion of water?

What is the reason for anomalous expansion of water? Why don't it simply expands on heating or contract on cooling. Why it shows anomalous behavior at 4 degree centigrade? Why not on 4,6 or 10 (or ...
0
votes
1answer
27 views

Behaviour of water at exactly 0°C

If I had a beaker of water (i.e. many molecules), at exactly $0^{\circ}C$ and at atmospheric pressure, what phase would be encountered? And would the answer to this also apply to other substances at ...
0
votes
1answer
29 views

Hydrate questions

Two questions that I'm really stuck on: A sample of cobalt(II) nitrate hydrate was heated to remove all the water of hydration. The hydrate was found to be 65.96% oxygen. Calculate the number of ...
2
votes
0answers
35 views

Specific Heat of Water Solution

If we add an ionic solute to water, will the specific heat of the water be increased or decreased? I understand that the specific heat is a measure of how much energy we must add to water for the ...
1
vote
2answers
24 views

Water purification procedure that does not involve a flocculant of any kind?

I have read about "electroflocculation" that uses less flocculant/alum, but is there a method – no matter how expensive or impractical – that uses no flocculant at all?
3
votes
2answers
54 views

What's the Acid Ionization Constant of the Hydrogen Proton?

What is the $\ce{K_{a}}$ value for $\ce{H^+}$. I understand that the hydrogen proton doesn't stick around in solution by itself for very long. Nonetheless, does it have a $\ce{K_{a}}$ value? Can it ...
9
votes
3answers
3k views

Why doesn't a table sublimate, while ice does?

A table does not sublimate, and nor does a spoon. Ice does, however. What is the fundamental difference?
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0answers
55 views

How to break down soap and detergents?

I am building a greywater harvesting system. I have all of it designed except one aspect. It is a 3 phase system. The first phase breaks down soap and detergents. The second phase filters the water. ...
2
votes
2answers
109 views

Why $\ce{MgSO4.\color\red{7}H2O}$?

I was wondering why specific number of water molecules are attached to salts like $\ce{CuSO4.5H2O}$? Searching gave me a satisfying picture : I think $\ce{FeSO4.7H2O}$ should have a similar ...
2
votes
3answers
83 views

1-octanol in polar but immiscible with water

1-octanol is polar due to the presence of the -OH group but it is immiscible with water. How is it possible?
6
votes
1answer
215 views

Why does the water in a Powerade bottle tastes a little like Powerade after many refills?

I have a bottle of Powerade and after probably around 20+ refills of water, the new water I put in still tastes/smells a little like Powerade. How does that happen?
3
votes
2answers
94 views

How can water be electrolysed if it's not ionic compound?

The electrodes have different charges. One is positive ( the cathode ) while one is negative (anode). They will attract the particles in the solution which are charged. Hydrogen to the cathode ...
1
vote
1answer
107 views

Why does water volume decrease when salt is added?

help me to know the reason why does water volume decrease when salt is added? our teacher asks us in the class but I don't find any strong reason.please help me.
0
votes
2answers
67 views

Configuration of a water molecule?

Water molecules are described as an oxygen atom covalently (ignoring for the monent protonization/deprotonization) bonded to two hydrogen atoms with an angle of ~104° between the hydrogen atoms (like ...
3
votes
1answer
76 views

Instantly seperate oil and water

I have a solution of water and oil mixed to as much as possible, since they won't actually mix. The supply is coming down a pipe at a relatively fast rate and I need to separate it so that the water ...
0
votes
1answer
31 views

What happens to water under high pressures without possibility of escape?

Knowing very little about the nature of water, wondering how it might behave at the centre of a planet or centre of an another massive gravitational body. Could water take such pressures or might it ...
3
votes
1answer
69 views

Time taken in changing surface tension

I had read some where that in glasses the surface tension is high, but in a lota the surface tension is low. My question how much time does the surface tension take to change? I mean that there was ...
1
vote
1answer
118 views

Yama Cold Brew Tower: what are these lab parts / components?

When viewing this on a shopping web site, one of the reviewers indicates "This is about 50-60 [dollars] worth of pyrex glass and another 20 [dollars] worth of wood." The company charges $499 for this ...
3
votes
1answer
70 views

Most common material in the universe

I was told that 'water' was the most common material in the universe and I disputed that claim. I was met with the argument that hydrogen and oxygen were the most common atoms in the world so water ...
22
votes
5answers
5k views

Does water really 'go bad' after a couple of days?

Among my friends it is a sort of 'common wisdom' that you should throw away water after a couple of days if it was taken from the tap and stored in a bottle outside the fridge, because it has 'gone ...
6
votes
2answers
839 views

How to separate HCl and NaOH from salt and water solution?

I mean, how can we reverse the neutralization reaction of HCl and NaOH to get back HCl and NaOH. I want to extract HCl and NaOH from a mixture of common salt and distilled water in equal proportions ...
2
votes
1answer
98 views

Products of the o-Toluidine oxidation with glucose oxidase and peroxidase

Could anybody describe which product is formed in the following reaction (o-Toluidine oxidation)? $$\ce{H2O2 + o-Toluidine_{uncolored} - Peroxidase -> H2O + 1/2 O2 + o-Toluidine\; ...
0
votes
2answers
646 views

How does High Frequency water electrolysis work?

I have read that combining the DC current with a high frequency AC current, the electrolysis of water speeds up. How does this work? Does the "extra energy" come from less heat production? What ...
1
vote
3answers
60 views

Dihydrogen monoxide

Is the name "Dihydrogen monoxide" actually what chemists would use to refer to H2O (assuming there was no common name, "water")? Of course, this is all over the internet. I'm a little skeptical ...
1
vote
1answer
27 views

How to make something solid that dissolves faster than bar soap in water

What is a soap-like material that holds a solid shape, but dissolves completely in water over 10-15 minutes. Think disappearing Rubber Ducky.
0
votes
1answer
32 views

Hydration of lithium salts

Why are lithium salts heavily hydrated? I am not able to understand this because I feel salts of larger cations like Caesium should be more hydrated because of the larger size, they can able to hold ...
3
votes
1answer
437 views

Determining standard Gibbs free energy for water?

I am dealing with the dissociation of water into its components hydrogen and oxygen and I am trying to determine the standard Gibbs free energies of each component. My professor said if the substance ...
3
votes
1answer
66 views

Smelly matters in urine - do they have lower or higher boiling point than water?

I don't know what exactly are the compounds that causes urine to be smelly, but does it (or do they) have higher or lower boiling points than water? If I have both liquid and exposed them to open air, ...
5
votes
2answers
122 views

Is tea powder better dissolved when put in hot water?

I usually make tea by adding two spoons of tea powder to water at room temp. and start to heat it. My friend said it will be better to add the powder once the water starts boiling. She said that it ...
0
votes
1answer
81 views

Ionic Product of Water

Why is the ionic product for water ($K_w$) temperature dependent? The concentration of $\ce{H+}$ and $\ce{OH-}$ ions in pure water is $\ce{[H+] = [OH^{-}]} = 1.0\times 10^{-7} M$ at $25^{o}C$, and ...
2
votes
3answers
170 views

Is there a hydrophobic gas?

I am looking into the subject of water repelling and have been led to the hydrophobic subject area. I have two questions regarding this subject. Is there a hydrophobic gas ? If a hydrophobic ...
8
votes
2answers
281 views

Can an aqueous solution conduct electricity forever?

We know that pure water does not conduct electricity, but salt water is a decent conductor. This is commonly explained by saying that "the ions carry the current through the solution", an explanation ...
7
votes
1answer
535 views

Why is water wet and fire hot?

This may be a silly question but why is water wet? All the previous questions on water do not explain the reason why is water wet. They assume that its a natural property. However we need to ...