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

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2
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1answer
53 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
26 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
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1answer
51 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
38 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
56 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 ...
19
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5answers
4k 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 ...
5
votes
2answers
458 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
60 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
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2answers
118 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
54 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
16 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
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1answer
19 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
109 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
57 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, ...
4
votes
2answers
84 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
63 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
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3answers
134 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 ...
7
votes
2answers
195 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 ...
6
votes
1answer
237 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 ...
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0answers
21 views

Can you heat water with chemical additives? Would it remain safe to drink? [duplicate]

I've been wondering, is there some chemical that reacts with water, causes heat but isn't toxic?
6
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3answers
328 views

Is pure water very corrosive?

In other site, someone claimed that pure water is very corrosive. Water distilled for some laboratory uses (like the Z-pinch reactor) is distilled to 0.00000009% purity, and is caustic enough to ...
3
votes
2answers
415 views

Why does water evaporate at room temperature?

When water temperature reaches $100^\circ C$, the molecules get so excited that the hydrogen atoms lose the bonds to the oxygen atom and therefore the water starts to become gas. I get that, but at ...
3
votes
1answer
85 views

What can cause artesian well water to smell?

Recently, our water from the artesian well started to smell (again). It only smells bad for only few seconds than the smell disappear. We have sulfur-iron removal system, water softener, UV lamp. ...
5
votes
2answers
249 views

Why does water cause a jet flame when poured over a bunch of tealights?

A neat party trick (typically for outdoors) is to build a pyramid of tealights, let them burn for a while and then pour a bit of water over it and see a large jet flame shoot out (see e.g. this ...
1
vote
1answer
84 views

Why distinguish between polarity and hydrophobicity?

I have yet to see an example of a molecule that's both polar and hydrophobic or that's both non-polar an hydrophilic. If no such molecule exists, why use the terms "hydrophilic" and "hydrophobic" at ...
0
votes
1answer
61 views

Quantifying Ascorbic Acid in Soft Drink

I have access to a GC/MS, FID, and a spectrophotometer. My first thought was to derivatize with trimethylsilylating agent, then run it by GC. Unfortunately the water is problematic. Heating it is ...
6
votes
1answer
77 views

When and how in anaerobic digestion is water dissociated?

Anaerobic digestion and methanisation of organic feedstocks is a complex series of processes that result in biogas. One way to look at this is a very top-down, stochiometric approach as in the Buswell ...
1
vote
0answers
56 views

Electrolysis Lab

How do I keep hydrogen or oxygen in a test tube when pulling them out of water? I have a styrofoam cup with two metal thumbtacks pushed though the bottom and about 100 ml of distilled water mixed with ...
1
vote
0answers
70 views

Coffee and tap water reaction - results in gray tint

I use filtered water to make my coffee. If I mix a few drops of said coffee with our tap water, it turns a grayish color; it's much darker than the coffee would turn the water by itself (I compared ...
2
votes
2answers
99 views

Why do hairs (rubbed with plastic comb) fallen on water seems to be sticking?

I was observing from many days, how hairs seems to be sticking to water, when made to fall on it. I made an attempt to know what really was going on. I kept a jug of stationary water under the light, ...
1
vote
2answers
118 views

Why do puffed rice stick to wet hands?

My mom gave puffed rice to eat, I had quite wet hands. I saw that, each puffed rice pieces started hanging to the hand, when I brought my hand in contact with them. I thought about electrostatics ...
8
votes
2answers
321 views

Why does water dissociate to H3O+ and OH- rather than H+ and OH-?

Why does water dissociate to $\ce{H_{3}O^{+} + OH^{-}}$ instead of $\ce{H^{+} + OH^{-}}$? This question came to surface when I was learning about acids and bases, and learned this definition: ...
1
vote
1answer
69 views

What is the solid crud that appears inside my kettle?

Almost every share-house I've lived in has had some nasty looking solids collecting inside. I always regret looking inside the kettle because a cup of tea never tastes quite as good after you've seen ...
0
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0answers
48 views

How effectively bound Na2CO3 and BaCL2 water

How fast does $\ce{BaCl2}$ bind water from its surroundings, becoming a hydrate, compared with same process with $\ce{Na2CO3}$?
0
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1answer
65 views

Can freezing break up sugar polymers?

I recently freezed a huge bunch of apple slices, and thawed them again a few days later. After thawing, I noticed a few things compared to a batch that I had put in the fridge (no freezing) The ...
3
votes
1answer
51 views

How much water vapour can a gram of Uppsalite absorb at NTP?

This site writes to say It turned out that Upsalite had the highest surface area measured for an alkali earth metal carbonate; 800 square meters per gram. Assuming that a sphere may enclose the ...
3
votes
1answer
249 views

How to make artificial sea water

My 7th grader is embarking on a long-term science project and I'm on tap to "help." He is showing a strong interest into finding ways to get drinking water to the masses. His idea is that we need to ...
2
votes
1answer
115 views

Why was anhydrous magnesium carbonate “upsalite” discovered so late?

What complicated the synthesis of upsalite (anhydrous MgCO3), for it to be synthesized and published in 2013 as opposed to the 20th century, as one would expect for such a simple salt?
5
votes
2answers
217 views

Can 1 mole of H2 react partially with one mole of O2?

I am currently studying stoichiometry (high school level) and we came across the following equation in school: $\ce{2H2 + 1O2 -> 2H2O}$ which is clear to me. We learned in school that reactions ...
4
votes
1answer
141 views

Why is it not dangerous to dissolve NaCl?

$$\ce{H2O_{(l)} + NaCl_{(s)} ->[\Delta] Na+_{(aq)} + Cl-_{(aq)}}$$ When table salt is placed in water, it dissolves due to the polarity of water molecules. When solvation takes place, negatively ...
3
votes
1answer
92 views

How to get the freeze point of mixed liquids?

I recently bought in Italy a bottle of "Alcool puro" which is in fact 95% Alcohol and 5 % Water. So alcohol has a freezing point of -114°C and water a freezing point of 0°C. How can I calculate then ...
2
votes
1answer
160 views

How much heat is required to dehydrate a hydrate?

If I have a hydrate, such as copper (II) sulfate pentahydrate, $\ce{CuSO_4 \cdot 5H_2O}$, what is the amount of heat to required to dehydrate it? I assume that it is equal to or greater than the ...
-2
votes
1answer
108 views

Are there any commericially available hydrophilic solids available to the public?

I am looking for available hydrophilic solids at room temperature that a regular consumer can purchase. It would be better if it were a flexible membrane, but it does not have to be. The function of ...
5
votes
2answers
158 views

Is real water made up of heavy water and light water?

I need to know, is real water made up of heavy water which is formed with deuterium, and light water which is water by protium? We know that hydrogen has three major isotopes, including protium and ...
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0answers
110 views

Does the temperature of water change during electrolysis?

Applying an electric potential to impure water splits water into its constituents H/O. Does the temperature of the electrolyte change during this electrolysis?
8
votes
2answers
358 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 ...
5
votes
2answers
3k views

EZ-Water - Fraud or breakthrough?

Recently the quack medicine folks online have been promoting the research of a certain Dr. Gerald Pollack who claims to have discovered a "forth phase of water", and who has recently published a book ...
6
votes
4answers
649 views

Why can't pure water conduct electricity since it can be reduced at cathode and oxidised at anode?

We all know that pure water can't conduct electricity. But during electrolysis, if add a small amount of HCL acid inside, water could be decomposed to hydrogen gas and oxygen gas, as it is reduced at ...
4
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2answers
189 views

Sodium Hypochlorite Production Explanation

One reaction used to form sodium hypochlorite (A type of bleach) is as follows: $\ce{2NaOH(aq) +Cl2(g)->NaOCl(aq) + NaCl(aq) + H2O(l)}$ Provided the sodium hydroxide is dissolved in some ...