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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How does adding sucrose to water affect its specific heat capacity?

I conducted an experiment to determine whether adding sucrose to water affects its specific heat capacity. I have noticed that solutions containing the most amount of sucrose tend to have a lower ...
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The use of far-infrared ceramics for water purification?

I am struggling to understand how exactly far infrared ceramic balls help purify the water. It is stated that active ceramic taormine balls help purify the water by forming a 2 micrometer wavelength ...
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How does water sublimate at normal atmospheric pressures/conditions (i.e., without a phase boundary between solid and gas)?

I remember my high school chemistry teacher stating that water could sublime under normal atmospheric conditions that would exist in e.g., Lancaster County, PA, where Amish would hang clothes to dry ...
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pH of water on paper vs meter

We have both a professional (lab) pH meter, and several different version of lab grade pH paper, but are experiencing a very weird phenomenon. We have calibrated all the papers against standards, and ...
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Specifically how does the presence of moisture and oxygen affect the yield of ferrocene? [closed]

In a lab this week at uni we made ferrocene (I'm a second year Chemistry student). This was done by reacting nBuLi with cyclopentadiene (kept in freezer) to create the Cp anion in-situ. To this ...
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Hydrophobic effect/interactions

$\text{Water molecules cause hydrophobic interactions because:}$ $\text{A- they can disrupt surfaces with no hydrogen bonds.}$ $\text{B- they prefer to be close to hydrophobic surfaces}$ $\text{C- ...
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Can addition of a "neutral" salt like NaCl assist pH test strip measurement accuracy in low ionic strength/poorly buffered solutions?

After a web-search, it seems ISAs (Ionic Strength Adjusters) are offered commercially to assist pH electrode/probe measurements. Presumably meant to increase conductivity (without affecting pH ...
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1answer
43 views

Using a pH meter to measure the presence of water in liquid ammonia? [closed]

I intend to do some experiments with building an ammonia-water gas adsorption refrigerator similar to a Crosley Icyball Wikipedia - Icyball. When recharging the icyball, it is important to not ...
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How to calculate/estimate the contamination rate of ultra pure water (UPW) in the presence of metals?

Metals are known to release ions into ultra pure water. Do any equations or empirical data sets exist for estimating the rate of contamination with different metals? I don't need a specific solution; ...
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Characteristics of metals compatible with semiconductor grade Ultra Pure Water (UPW)?

I am looking to build a water conductivity sensor for semiconductor grade Ultra Pure Water (UPW). UPW conductivity sensors already exist, but because of price and low water volume I need to fabricate ...
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how dilute should the solution be for a noticeable enough colligative property such as relative lowering in vapor pressure?

I was mixing soup powder with boiling water today and noticed the vapors coming from the water suddenly vanish; seemed like the powder being non volatile decreased the mole fraction of water in the ...
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How to make a steady supply of water from a supply of H2 and O2

writing a survival novel where a guy needs to survive and needs to make water to do so. It is on another planet and he access to sci-fi type manufacturing machines that can make most tings. He has a ...
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Nanoscale hydrogen batteries that use water-splitting technology

It was claimed in this article in 2019 that a nano-battery using water splitting technology is developed. It is described as: The battery gains its charge by interacting with water molecules present ...
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Pressure increase in a chamber with 1 ml of water heated to 200 °C [closed]

For safety reasons I want to know how much pressure will be generated in a sealed chamber with $1~\mathrm{ml}$ of water, pure nitrogen at $1.3~\mathrm{bar}$ at $22~\mathrm{^\circ C}$. This chamber ...
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Preventing water from freezing (-20 °C) in a vinyl container [closed]

What is a safe anti-freezing liquid to use to dilute water, to prevent it from freezing at -20°C, without damaging the vinyl container it's stored in? This container is a heavy bag, for punching. So ...
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Are there any cold temperature reactions in liquid where ice forms as a precipitate?

The title asks the entire question, but I'll elaborate: Precipitates form in aqueous reactions when some product is insoluble in water. Is there a reaction in some other solvent where solid water ...
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How does part of frozen liquid ( like soup) boil and still be frozen at same time if temperature stays same while melting?

I was reading the following basic question about temperature change during phase change (During phase change in matter, why doesn't the temperature change?), and the answers provided clearly ...
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water to hydrogen to water [closed]

I'm trying to find out if there is any loss of water when converting water to hydrogen and then back into water and can't find an answer anywhere I've searched. I understand that the water produced is ...
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Which reaction is happening in the preparation of sulfuric acid through contact process?

I've read that in the preparation of $\ce{H2SO4}$ through the Contact process, on the absortion tower, the gas $\ce{SO3}$ is getting in contact with $\ce{H2SO4} (l)$ , because adding $\ce{SO3}$ to $\...
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Does distilled water still have ions in it? Does deionized water lack ions, but still have other "stuff" in it?

This isn't a question about the difference between Deionized and Distilled water, my hope is that for once it's actually a chemistry question related to this topic. Distilled water is created by ...
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24 views

How to make my water destillery most effective?

I got a destillery for water with a capacity of 10l and a get the most of a spiral cooler in a 1l cooling pot mounted on top. I'm happy with the efficiency, however there's always room for improvement ...
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Is there a difference in electrolsys rate limiting effects between electrodes of different area if one reverses the electrical polarity?

If one has two concentric stainless steel tubes with the small one being 1/2 the circumference and inside the other, and KOH for the electrolyte, then given the different surface areas between the ...
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I mix table salt and baking soda with water to make mouth rinse, and leave them for several days. It started to form precipitation, and a bad odor [closed]

I mixed 2 spoons of baking soda with 1 spoon of salt and mixed them with water (but not mixing totally) and left them for several days. At first I saw some bubble but the water was clear, but then it ...
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Water density in the calculation of the ionic product of water

In 2019 the International Association for the Properties of Water and Steam released this document for the semi-empirical calculation of the ionization constant of water: http://www.iapws.org/relguide/...
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Adding H2O2 in water does what to the pH of the water?

Not looking for numbers (unless required). I searched for this question on Google and found irrelevant results, with only the following link of some use but it doesn't appear to answer my question (...
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1answer
114 views

Mission: Impossible? Hydrocarbons in an aqueous liquid (e.g. humulene in beer)

Your mission, should you decide to accept it, is to describe how hydrocarbons can be stably mixed into a water-based liquid such as beer, as in this question. According to the usual textbook wisdom, ...
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49 views

Hazardousness of Chlorothalonil & metabolites in shower water? [closed]

Recently it came out, that in some parts of Switzerland (where I live), there is Chlorothalonil & metabolites/breakdown-products of it in the drinking water. Yikes. Problem is, chlorothalonil ...
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61 views

Computational determination of the diagram of molecular orbitals of a polyatomic chemical species

A diagram of molecular orbitals for $\ce{H2O}$ would be as follows: The above diagram has been constructed qualitatively following the steps that I have been instructed in various classes on this ...
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Can stainless steel be electrically insulated with (oven-dried) Sodium Silicate Solution?

Can I electrically insulate stainless steel by painting Sodium Silicate solution on it and heating it to 200C for 30min or so? The solution should be conductive, and I've been told (to be verified) ...
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1answer
111 views

In an open system, can water vapor escape into the atmosphere before reaching the boiling point? [duplicate]

In a closed system, water vapor would have nowhere to go and atmospheric pressure would not be a factor. It would reach dynamic equilibrium with only water vapor. But in an open system, I think that ...
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What happens to water and oxygen produced due to dissociation of nitric acid? [closed]

Nitric acid is yellow in colour due to the dissolution of nitrogen dioxide gas. The nitrogen dioxide is obtained due to thermal dissociation of a portion of nitric acid: $$\ce{4HNO3 -> 2H2O + 4NO2 +...
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Why is NaCl so abundant in the ocean [closed]

Why is sodium chloride far and away the most abundant salt dissolved in ocean water. Its two constituent ions do have a very high frequency in the crust of the earth but they are far from the most ...
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How can I save an EEM file on a Fluoromax4?

I'm trying to run excitation-emission matrices on some water samples, but I'm running into some software issues that the manuals aren't helpful for. In order to use R studio to extract my data, I need ...
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How can I set up and process my excitation-emission matrices properly?

I'm running EEMS on some water samples on a Horiba Fluoromax 4 spectrofluorometer. Method below. $\pu{240-580nm}$ emission, $\pu{5nm}$ interval, $\pu{1nm}$ width. $\pu{240-480nm}$ excitation, $\pu{...
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1answer
689 views

Volume of Oxygen Produced By Electrolysis of Water [closed]

I am trying to estimate the volume of oxygen that will be produced by electrolysis of water at normal temperature and pressure with a current of $\pu{50 A}$. The following is my calculation: The ...
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233 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 ...
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is electrolysis of water less efficient with warm water? E.g 40, 50, 60... °C

I see there is High-temperature electrolysis which is a whole different animal than room temp electrolysis. I want to know if electrolysis of lukewarm water will behave much differently. My guess is ...
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85 views

On the molybdenum(III) oxide-catalysed oxidation of alkanes to carbonyls

The following reaction is specified in my notes; $$\ce{CH4 ->[Mo2O3, \Delta]HCHO}$$ The intermediate steps involve the dehydration of an alcohol to yield the final product. Wouldn't this only work ...
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Why does the addition of heavy water cause OH and NH peaks in NMR spectra to disappear?

When $\ce{D2O}$ is added to a sample, the OH and NH peaks in a $\ce{^1H}$ NMR spectrum disappear. This is the basis of (for example) the $\ce{D2O}$ shake test, and is also the reason why peptide/...
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Is there a relation between polarity of molecules and their electric susceptibility?

So it is written in our text that electric susceptibility ($χe$) (the response of say water molecules in the presence of an external electric field) is related to the molecular behaviour of various ...
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100 views

Finding the charge passed in electrolysis of water using volume of hydrogen released [closed]

During the electrolysis of water we have gotten $\pu{10 dm3}$ of hydrogen. Temperature was $\pu{0 °C}$ and pressure was $\pu{101325 Pa}$. What charge has passed trough the electrolysis article/joint? ...
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Hydrogen peroxide on damp clothes left out in the sun [duplicate]

Somebody told me that sunlight is a good bleach for clothes because leaving damp clothes outside in the sunlight will turn some of the water into hydrogen peroxide. Is this true. If yes, then why can'...
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570 views

Which process would separate the mixture of toluene, cyclohexane and water?

toluene: $\ce{C6H5-CH3}$ cyclohexane: $\ce{C6H12}$ I think that answer would be: Toluene and cyclohexane do not dissolve in water (since they are nonpolar), so I would first separate the water from ...
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CCSD and CISD size consistency problem

I have performed a Gaussian16 calculation to explore the size-consistency problem for the CISD and CCSD methods. The system I am studying is the water dimer and the results are not what I expected at ...
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Electrolysis of water using different kind of electrode and electrolyte safest as possible for splitting demonstration

I am planning to electrolyze water for an experiment. However, I have limited resources and want to do it as safely as possible The resources that I have: $\pu{12 V}$ DC battery Graphite (in the ...
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229 views

How does the relationship between carbonate, pH, and dissolved carbon dioxide work in water?

Fish keepers use a table like the one below to determine dissolved $\ce{CO2}$ by observing the color of a pH indicator in water with a known concentration carbonate solution (typically 4 degrees KH ~= ...
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Milliliters of NaBr when changing molarity [closed]

I was very confused by this problem. I was able to get the molarity, but I wasn’t certain how to go from there: If $\pu{2.60 g}$ of $\ce{NaBr}$ is dissolved in enough water to make $\pu{160.0 mL}$ of ...
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Will water interfere with an in-situ XAS measurement of the Pt L3 edge during OER on a water electrolysis cell?

I am trying to design a cell for an in-situ experiment. As much as possible, I was hoping to be able to do it on a PEM MEA rather than on a half cell immersed on an electrolyte. I am thinking that ...
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37 views

Hard water filtration

Why does hard water have to pass through the cation exchange resin first followed by the anion exchange resin? Why can't it be the other way around?
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68 views

What is the heaviest possible water using oxygen and hydrogen isotopes, and what might it's physical properties be? [closed]

After a cursory internet search, it appears to me that Hydrogen-3 (a part of Tritiated Water) is the heaviest stable* hydrogen isotope. Oxygen-21 is the heaviest isotope of Oxygen with a half-life of ...

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