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

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Is distilled/deionizing water corrosive?

I've been reading up on distilled and deionized water and I've come across conflicting information. If compared to regular tap water there are little to no minerals, why are they used to clean ...
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1answer
28 views

Really understanding oncotic pressure and osmosis

I can't wrap my head around the idea of oncotic pressure and osmolarity, logically. I imagine a blood vessel. It is FILLED with proteins...Like a ton of proteins and solutes. So this means, according ...
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2answers
39 views

Have “molecular clusters” for azeotropes been identified?

A different question about azeotropes got me thinking about this point again. Azeotropes have a very specific composition so it seems that the azeotrope ought to have some sort of physical structure. ...
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0answers
4 views

What are the theoretical and actual (measured) minimum water potentials in plants?

I'm a plant physiology researcher, but water potentials are not really my thing, so I don't have a great grasp on the literature. I'm dealing with water potential data right now though, and it seems ...
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0answers
8 views

Method to extract Histamine from a liquid [closed]

Is there a method to extract Histamine from a liquid? I only found out that it is solvable in water. But my goal in this application is to only remove the Histamine. Thank you in advance for any help! ...
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1answer
21 views

Manipulate melting point of frozen water [duplicate]

How to manipulate water in way that ice melting point isn't 0°C, but for example 4°C?
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2answers
793 views

Are the lone pairs in water equivalent?

It sounds like a dumb question based on the way we draw water, but supposedly water is $sp^3$ hybridized, so one of those lone pairs should be in an $sp^3$ orbital and the other should be in a pure p ...
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2answers
5k views

What is the pH of ice?

The pH of pure liquid water depends on temperature. It is about pH = 7.0 at room temperature, pH = 6.1 at 100 °C, and pH = 7.5 at 0 °C. What happens to the pH (or to the ion product) of pure water ...
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6answers
13k views

Is it safe to drink reboiled water?

There have been some claims saying that drinking reboiled water is dangerous because it produces arsenic, nitrates, etc. Is this true?
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24 views

What makes the double displacement reaction:CaZ + 2 NaCl = Na2Z + CaCl2 (Z is zeolite) possible?

$\ce{CaZ + 2 NaCl -> Na2Z + CaCl2}$, where Z stands for zeolite. This is the reaction which generally occurs under removal of hardness of water during a process called Permutit or Ions exchange ...
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28 views

Moderately soluable

In solubility rules, there is some exceptions. It says for example: All sulfate ($\ce{SO4^2-}$) compounds are soluble except those of $\ce{Ba^2+}$, $\ce{Sr^2+}$, $\ce{Ca^2+}$, $\ce{Pb^2+}$, ...
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1answer
36 views

Does clay absorb water because of polarity?

From what I have recently learned about ceramics, clay is essentially sheets of silicon and oxygen, bonded by covalent bonds. Between them, water keeps clay from forming a full lattice of ...
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1answer
43 views

Does hydrogen bonding contribute in solubility of a substance

If a compound can't hydrogen bond with itself but can hydrogen bond with the water, why does it still remain immiscible? Take for example ethoxyethane. It can't hydrogen bond with itself but its ...
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1answer
70 views

What is a hydrogen bond?

I was doing a little research on the Chemistry of water, and it said that water molecules have a hydrogen bond between them. What is it, and what does it do to water?
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0answers
19 views

Washable Pen Ink in Water - Colour Change

So I have a fountain pen that uses "washable" black ink cartridges. I haven't used it in quite a while. Having left it for some time with no ink it all dried up and I've been trying to get it going ...
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0answers
121 views

Does a microwave oven act on the principle of giving vibrational or rotational energy to water molecules? [closed]

Does a microwave oven act on the principle of giving vibrational energy to water molecules or by giving rotational energy to water molecules? I tried to google it but answers are not specific where as ...
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0answers
17 views

reduce pollutants in cooking water

I am looking for a simple method to reduce Arsenic and other pollutants in cooking water, possibly not using filters. My aim is not to obtain perfect drinking water, but just to reduce the absorption ...
0
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1answer
112 views

Calculating temperature after adding heat to ice

If $53.2~\mathrm{kJ}$ of heat are added to $15.5~\mathrm{g}$ of ice at $-5^\circ\mathrm{C}$, what will be the resultant state of matter in which water is present and also calculate its final ...
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1answer
60 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.
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2answers
37 views

Why did a former emulsion of oil and water precipitate after heating and cooling when heat made it originally?

I added 100 g coconut oil, 100 g distilled water and 500 mg lecithin to an 1800 watt blender. The motor from the blender has has a passive heating action. I blended it at full for four minutes. The ...
3
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0answers
25 views

Why does chromium metal not react with a solution of Mg^2+ even though their standard cell potentials produce a net positive voltages?

Write net equations for the spontaneous redox reactions that occur during the following or NONE if there is no extensive reaction. Use the lowest possible coefficients. Include states-of-matter ...
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0answers
20 views

Acetic acid synthesis

I made some acetic acid by bubbling ethenone through water, but my weight calculations don't make any sense, so I think there were some side products along with the acetic acid. What are they, and ...
8
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1answer
162 views

Can H4O 2+ form?

Like $\ce{NH4+}$ ,Is there any possibility of formation of $\ce{H4O^{2+}}$ (of tetrahedral structure)? My theory is: it can be formed by osmosis setup where heavy acids like $\ce{H3PO4}$ or ...
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1answer
53 views

Is water committed to vapor state at boiling point or after? [duplicate]

Quite early into my studies, I learnt about phase changes with this graph. I’m just going to focus on vaporization/condensation. I learnt that the plateau was caused because all the heat was going ...
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1answer
37 views

Supersaturated gas solution

Can you make a supersaturated gas solution? As we know solubility decreases when we increase the temperature, So If I do that, will the gas molecules escape the solution or will they stay in the ...
3
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1answer
48 views

Is HCl(l) acidic?

If in a reaction mixture HCl is given in liquid phase, will it behave as an acid ? I know that an aqueous solution of HCl is acidic but am confused about the liquid phase.
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2answers
44 views

Molar concentration of water and pKa value

By defintion, $\mathrm pK_\mathrm a$ value is defined as $$\mathrm pK_\mathrm a = -\lg ([\ce{H2O}] K_\mathrm{eq})$$ Consider the reaction: $$\ce{HCl + H2O <=> H3O+ + Cl-}$$ The Eq constant of ...
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37 views

Interactions between water and oil

I haven't thought about the forces that attracts oil to water (it is weak). The attractions between water molecules are caused by hydrogen bonds (primly), while oil through London forces. But between ...
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0answers
48 views

Separate toluene from acetone and isopropyl alcohol

I found a Cellulose Thinner, that is made of toluene 60-80%, acetone 10-20%, and 2-propanol 5-10%. As acetone and 2-propanol are water soluble, but toluene isn't, would it be possible to just add a ...
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2answers
47 views

Autoprotolysis Constant of Water

My chemistry textbook states that $[\ce{H3O+}][\ce{OH-}] = K_w$ in all aqueous solutions, which we know of as $K_w$. However, I was wondering why this was true. The textbook states that it is true ...
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1answer
162 views

Is organic carbon the same thing as organic compounds?

Are they the same thing or is there some minute difference? I have looked all over the web and you would think this would be a common question but I can't find any answer. If they are different then ...
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0answers
23 views

Why can cloud's bottoms be flat?

I've always wondered why clouds can have flat bottoms, and have debated to myself whether it was a difference in atmospheric pressures, or some water molecule tendency? Could someone shed light?
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1answer
97 views

Does glycerin promote bacterial growth the same as water?

A sodium chloride + water solution draws the water out from bacteria through the process of osmosis. Would a sodium chloride + glycerin solution have the same antibacterial effect? If I understand ...
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2answers
171 views

Is there an easy way to test for the amount of iron (Fe) in water?

I have a rusty metal rainwater tank, and I'd like to find the amount of iron in the water. (The water I've collected is perfectly clear.) How would chemists in the 1800's have gone about this? What ...
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2answers
106 views

How would mixing sea salt and honey affect the water activity of honey?

Honey has around 20% water content which is one mechanism of it's antibacterial action. If I mixed equal parts of honey and salt how would this affect the water content/activity of honey? Would it ...
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1answer
23 views

Is there Any Advantage to Using Multiple Steel Plates in an Electrolyzer?

If I have an electrolyzer (For water) is there any advantage to having additional steel plates in between the electrodes in solution? For some reason this appears to be a popular design and I'm not ...
8
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1answer
213 views

Materials with solid volume greater than liquid volume

Water has a solid volume greater than its liquid volume. This question is in two parts. 1) Are there other materials that have solid volumes greater than liquid volumes? 2) What about the structure ...
4
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1answer
56 views

To extend the life of a cartridge razor blade, should the blade be stored in oil or alcohol?

I've read varied recommendations about extending the life of a razor blade. Some say should stick the blade in oil when not in use, others say in alcohol, others say in a bowl of rice or silica gel. ...
4
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1answer
31 views

Where can I access raw values for near infra red absorbance of liquid water?

I have encountered several sites where water's near-infra-red absorption spectra has been plotted as a figure (for e.g, here). Is there a site where I can access these raw absorbance/transmittance ...
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51 views

What are the physical properties of exotic ice?

This chart shows the phases of water that form at various combinations of pressures and temperatures. It has multiple exotic forms of ice (labeled II through XV) listed. What are the physical ...
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0answers
367 views

diH2O, dH2O, and DI H2O. What do they mean?

What do $\ce{diH_2O, dH_2O}$, and $\ce{DI H_2O}$ mean? I'm not asking for a description of deionized water and distilled water. I'm asking what the three abbreviations/formulas mean. In other words, ...
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0answers
39 views

What could cause one brand of carbonated water to be superiorly carbonated compared to another?

I buy a lot of carbonated water, its pretty much all I drink. There is something I've noticed that just made me curious though - The usual brand I buy is the cheapest one available, 14 cents per ...
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1answer
32 views

Predicting changes in pH of water when chlorinating using two different methods

Two methods for chlorinating water are using Chlorine gas ($\ce{Cl2}$) or calcium hypochlorite ($\ce{Ca(OCl)2}$). By using chemical equations how can you predict the pH of the water brought about by ...
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1answer
50 views

Comparing Methods of Determination of Dissolved Oxygen Content in Water Sample

I am currently doing an IB Chemistry Individual Investigation on dissolved oxygen in water samples by using Winkler method. However, my teacher suggested that I have to use oxygen probe as a standard ...
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4answers
226 views

Is Cold water heavier than hot water?

I have come across this Quora Answer where it was written that cold water is heavier than hot water. Are there any proofs which support it?
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0answers
16 views

Is the water in hydrated salts held in place by a type of bond? [duplicate]

See title And if so, what type? If not, why does the water stay in the salt? (I wanted to add salt as a tag, but I need 300 reputation for that. Could someone higher up please add that tag? I think ...
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2answers
83 views

Acceptable levels of HCl?

For a science/engineering project we are taking pool water (disinfected), filtering to 0.1 microns, and pumping to the kitchen. Of course there is still 5 ppm of chlorine present so we want to ...
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1answer
140 views

What is the difference between carbon and charcoal filters?

I'm confused about the difference between carbon and charcoal filters. Ultimately, charcoal contains carbon but I have come across an exam question that asks for their individual roles in a water ...
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2answers
234 views

Why does the ink on my whiteboard move?

...or at least I thought so, when I saw that the ink that was on my whiteboard last night became really messed up the next day. The image below shows my whiteboard before (on the left) and after (on ...