Questions tagged [water]

For questions relating to water (H₂O), specifically its structure, properties, and uses in chemistry. For questions not about water but rather about solutions in water, use tags [aqueous-solution] or [solubility] instead.

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60 views

For what chemical purpose did soldiers in WW2 carry small ion exchange resin columns in their survival kits?

My textbook [Chemistry Live, Declan Kennedy] states that ''During WW2 small ion exchange resin columns were part of a soldier's survival kit.''. I can't find any further info about this online or ...
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4answers
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Any idea why tap water goes stale overnight? [duplicate]

We have great tap water here in Hungary. My only problem that it goes stale overnight sometimes in some glasses or sometimes even the 2L water boiler has this problem too. But microbes cannot resist ...
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1answer
212 views

Order of solubility of sodium halides and potassium iodide

Order the following ionic compounds in decreasing order according to their ease to dissolve in water. a) NaBr; b) KI; c) NaF; d) NaCl. d > a > b > c a > b > c > d b > c > d &...
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Material Properties Dealing with “Wetting”

I am designing a rain device, and I am interested in a set of common metrics / standards for determining how something gets "wet". (1) Is there a "water absorbance" metric for ...
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1answer
25 views

When converting between a hydrated electrolyte amount in mass and in milliequivalents (meq), why are the water molecules taken into account?

A textbook I'm reading called "Ansel's Pharmaceutical Calculations, 13th edition" defines the milliequivalent (meq) thus (p. 187): This unit of measure is related to the total number of ...
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1answer
93 views

How to differentiate hydrous and anhydrous compound? [closed]

For an experiment, my teacher gave me containers of hydrates and their corresponding anhydrous compounds, but I have a feeling that for one of the compounds she switched the hydrate and anhydrous ...
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2answers
305 views

What is intermolecular distance in water? [closed]

I am wondering what is an average intermolecular distance in liquid water (say under normal pressure and room temperature). I need just order of magnitude. A reference would be helpful.
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1answer
64 views

Why does matter have spaces between them? [closed]

If you mix sugar Crystal in a glass of water and mix it well, the level of water will not rise.The reason they say is that matter have spaces between them.If matter have spaces between them , How ...
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1answer
87 views

What makes the enthalpy of hydration of calcium chloride dihydrate unique? [closed]

I have recently done an experiment in an attempt to find the relationship between the water ratio in a hydrate and the enthalpy of hydration, and my results showed a correlation, but an anomaly for ...
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31 views

Aluminum Monoacetate Solubility in Aqueous Medium?

Does anyone have access to the aqueous solubility value of aluminum monoacetate? I would expect it to be slightly soluble but I've searched the internet and haven't found any solubility values. : /
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1answer
134 views

Why is RO water more corrosive?

According to several articles from the American Water Works Association, permeate from RO should be stabilized in terms of pH and hardness to avoid corrosion of the distribution piping. How does ...
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1answer
52 views

Does hot water dissolve Copper more than cold water?

I read from WA state dept health https://www.doh.wa.gov/portals/1/Documents/pubs/331-178.pdf that hot water disolves copper more copper than cold water. Use cold water for drinking and cooking. ...
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51 views

When does copper leach to water? Conflicting faqs [closed]

I have heard conflicting reports: Copper leaches to water only when the water is high in acid or the Copper is corroded. Copper leaches to water any time, especially when it is new copper or the ...
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4answers
487 views

Explanation for a basic decomposition of water experiment

My son is trying to write a conclusion for a basic decomposition of water experiment using a 9 V battery (with a test tube placed over each terminal) placed inside a salt water solution. The results ...
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1answer
28 views

Why does ink form tendrils on wet paper [closed]

When a drop of ink or watercolour paint is placed on wet paper, rather than uniformly diffusing in all directions it forms tendrils which rapidly expand out from the spot. Why is this and what is the ...
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52 views

What is the most exothermic reaction with water? [closed]

What substance reacting with water at room temperature and atmospheric pressure produces the most heat (per mole)? Does anything beat fluoroantimonic acid?
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2answers
58 views

What are the properties of water in glaciers? [closed]

Does water from glaciers have many minerals (hard water) or would it be considered pure or distilled water?
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1answer
50 views

Deposition of saturated solution and affect of evaporated water

20g of water is evaporated from 200g of saturated solution of KNO3(aq) at 60°C by heating and the solution was cooled to 20°C. How many grams of KNO3 were deposited? The solubility of KNO3 in 100g of ...
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2answers
32 views

Effect of water vaporation on saturated solution

At a high temperature, water is evaporated from the saturated solution by heating. What is the solution losing exactly by the fact that the water left the saturated solution? Does it affect its ...
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1answer
30 views

The formation of ice crystals on/in frozen food that has been defrosted and then frozen again

I made a mistake. I put my ice cream in the refrigerator instead of the freezer and left it there for a night. I realized my folly the next day. I put it in the freezer. When I took it out, I noticed ...
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1answer
54 views

Must a desiccant be made anhydrous before it can be used for drying?

I'm writing about the treatment of methane gas, and in one part of the process, the methane gas is dried in a tank called a scrubber. Here, a desiccant called triethylene glycol is used. Thinking ...
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3answers
1k views

What is the equation for the reduction of water? [closed]

I'm a grade 12 student trying to understand redox reactions. What's the equation for the reduction of water? The back of my textbook says: $\ce{2H2O + 2e- -> H2 + 2OH-}$ I get that this makes sense,...
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0answers
76 views

How much D2O is in Vienna Standard Mean Ocean Water?

I'm curious how much $\ce{D2O}$ (heavy water) is in Vienna Standard Mean Ocean Water. I am interested in $\ce{D2O}$ molecules and not $\ce{HDO}$/$\ce{D+}$/ $\ce{DH2O+}$/$\ce{D2HO+}$/$\ce{D3O+}$ or any ...
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1answer
54 views

Why doesn't pure water conduct when it dissociates? [closed]

Sorry if this is an obvious question. I am told water dissociates, one product of which is negatively charged hydroxyl ions. This makes sense, but then why doesn't pure water conduct electricity? ...
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1answer
76 views

Are all gases equal in their ability to carry with them lower volatility matter at a given temperature? [closed]

As we all know water is a great solvent in it's liquid form relative to other substances. I wonder however how it performs as a gas relative to other stuff. Does anyone know how well steam carries ...
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1answer
25 views

Are there limits to waters energy absorbtion capacity

I have a system where I heat water in a flask. The water vapor generated is condensed and returns to the original container (not a pressurized system, but condensation system is efficient enough that ...
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0answers
11 views

What would happen if water is to flow through a microchannel where its top is hydrophilic and bottom hydrophobic?

What would happen if water is to flow through a microchannel where its top is hydrophilic and bottom hydrophobic? If an external pressure is applied, for example, a syringe pump is used, it is ...
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2answers
394 views

Does changing the electrolyte concentration in the electrolysis of water affect the speed that hydrogen gas is produced at the cathode?

I am currently completing a Year 12 Extended Practical Investigation. Due to the lock-down restrictions we are unable to complete our own practical experiment and have been given sample answers with ...
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25 views

Solubility Product, and it's relation to solubility

In order to remove temporary hardness of water, it is boiled. On boiling, while Ca(HCO3)2 gives CaCo3(ppt.) , Mg(HCO3)2 gives Mg(OH)2(ppt.). According to my book precipitation of Mg(OH)2 occurs due to ...
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1answer
40 views

Which salt is a surfactant and lowers the surface tension of the water? [closed]

I am doing my experiment on the surface tension of the water. How to show the decrease of surface tension of water with the increase in the concentration of salt? Is there any salt that lowers the ...
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2answers
75 views

How does the surface tension of water decrease with an increase in the concentration of NaCl?

Can anyone help me with the theory of surface tension? My chemistry experiment is related to the surface tension and concentration of NaCl. I am confused about my hypothesis. On the internet, I found ...
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104 views

How much 'stronger' is water vapor than carbon dioxide, molecule-per-molecule, over the course of a day, in terms of global warming potential?

I have read, many times, that water molecules are far more effective than CO2 molecules at trapping heat... But, the 'relative G.W.P.' value of water vapor (or its 'radiative forcing') is not listed ...
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1answer
33 views

How is the hydration state of a chemical related to its adsorption of water?

I am trying to understand adsorption and hydration states better, and I was thinking about the different hydration states of calcium sulfate - anhydrous ($\ce{CaSO4}$), hemihydrate ($\ce{CaSO4*1/2H2O}$...
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1answer
64 views

Turning sun into water [closed]

I don't know if this question belongs here or on physics stackexchange, but I believe it leans more towards this site. A friend of mine had a strange but funny shower thought. He said: "What ...
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0answers
104 views

Freezing point of solution of Water, Ethanol and Sugar (aka, Limoncello)

I'm looking for a diagram of the freezing point of a water solution depending on its content in sugar and ethanol. More colloquially, I want to know how to balance alcohol and sugar so that my ...
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1answer
250 views

Latent heat of vaporization/evaporation

It's the amount of heat required for liquid ---> gas phase change of a substance at it's Boiling point. But my question is, does providing energy equivalent to latent heat of vaporization to a ...
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1answer
37 views

Karl Fischer Titration simple explanation

I'm looking for a simple explanation how the Karl Fischer method to determine the content of water works. I'm not a chemist but an engineer from an electronic-physical field and my chemistry courses ...
2
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1answer
120 views

What is exposed in the surface tension of water?

(I guess) I understand the covalent bonding of water and the hydrogen bonding of water between two different molecules, but I would like to know which part is the part that that exposes itself to the ...
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0answers
161 views

Why does the solubility of haloalkanes in water decreases as the length of the carbon chain increases?

Due to the polar halogen-carbon bond in haloalkanes, they are more soluble than hydrocarbon in water. But the solubility is still very low because the overall influence of the dipole-dipole ...
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1answer
366 views

What happens when you put a battery in saltwater? [closed]

If somebody puts a battery in a salt solution, what path do the electrons take?
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1answer
82 views

Ice geometrical shapes [duplicate]

https://en.wikipedia.org/wiki/Ice https://www.google.com/search?q=ice&prmd=inmv&sxsrf=ALeKk028fJvrUcWLWu8EV-KsRGuiw0iWWw:1596098668929&source=lnms&tbm=isch&sa=X&ved=...
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1answer
65 views

Leaving Group Tendencies in Amide Hydrolysis

When we do hydrolysis of amides in basic conditions, we come across a mechanism in which the $\ce{OH-}$ ion attacks the carbonyl forming an intermediate as given in the photo: When the carbonyl gets ...
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52 views

What acids, solvents is lithium-6 fluoride soluble in (other than HF)?

$\ce{LiF}$ is quite insoluble in water, and I'm trying to use some water-soluble acid or solvent to dissolve $\ce{^6LiF}$ (95% enriched) in. I'm not a chemistry person, I'm a radiation detection ...
3
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1answer
245 views

Amine vs Amide Solubility

I had a question regarding the solubility of amines and amides. I was looking into the solubility of butanamide and n-Butylamine, and it turns out that whilst butylamine is miscible in water, the ...
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1answer
35 views

How to accelerate the evaporation of water at temperature below 5 °C? [closed]

How can we make the water to evaporate at low temperature? Does addition of high evaporating solvents help or decrease in the hydrogen bonding by addition of solute will help? Is there any other ...
2
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1answer
240 views

Why is a drop of chloroform stretched/pulled apart on a water surface?

I distributed drops of chloroform (with a lipid in them) on water (in a Langmuir-Blodgett trough). The chloroform drops form a layer on the water (so that the lipids are distributed on the water ...
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1answer
72 views

Does the depth of a lake affect how quickly its water is evaporated? [closed]

Suppose there are two freshwater lakes, each with identical surface areas and circumferences. One lake is 1 ft deep and the other is 20 ft deep. Although they exist in nature, lets assume they are ...
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1answer
75 views

How can I measure the scale in water?

I have hard water in my house. All the taps have tartar around. It generates some problems in some of my home appliances so I have bought polyphosphate salt but when I boil water I don´t get the ...
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1answer
367 views

Reaction Of Carbonic Acid With NaCl [duplicate]

I was just wondering if it was possible for anyone to specify what reaction conditions are required for the reaction between $\ce{H2CO3}$ (Carbonic Acid) and $\ce{NaCl}$ (Sodium chloride)? Does this ...
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1answer
68 views

Can elemental silicon react with water at room temperature and pressure? [closed]

Free silicon is not found in nature (in water, it might be present in the form Si(OH)4). So how is Si(OH)4 formed? Is there any possibilities of direct reaction with water?

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