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Questions tagged [aqueous-solution]

For questions relating to compounds dissolved in water and resulting reactions.

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Is iron(III) carbonate stable in water?

I searched for this onsite already, and also found the following answer on Quora: In aqueous environment, iron(III) is bound by water molecules and exists as $\ce{[Fe(H2O)6]^3+}$. Due to strong ...
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Where is my antimony going?

I work in a trace metals laboratory operating an ICP-OES. I've been having some trouble with the recovery of antimony in a weak $\ce{HCl}$ solution post-digestion. The antimony is part of a mix of ...
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Solubility of PbSO4

The solubility of $\ce{PbSO4(s)}$ increase with the addition of $\ce{H2SO4}.$ Why? I don't quite understand this. When dissolving $\ce{PbSO4(s)}$ we get the equilibrium equation: $$\ce{PbSO4(s) <=...
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Why does saline have a pH of 5.5?

I am a physician and administer 0.9% NaCl in water ("normal saline") to patients frequently. The bag says it has a pH of 5.5 (compared to the human body of 7.4). I am asking why the pH is so low. It ...
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106 views

How can copper(II) sulfate crystallize outside a glass vial?

I'm making copper sulfate crystals in glasses. Within a few weeks, the copper sulfate seems to crystallize both inside and outside the glass: (A few weeks after making a new solution) (Yet another ...
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Why does viscosity decrease when divalent cations are dissolved into aqueous solutions of sodium carboxymethylcellulose?

Sodium Carboxymethylcellulose (CMC/NaCMC/Aqualon) is a common product used in many instances for its unique properties, especially its ability to make solutions viscous. It is well known that the ...
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The Health Effects of Alkaline Ionized Water?

I came across alkaline ionized water as my aunts bought a system called Kangen Water from Enagic Inc. The water produced by this system is claimed to contain smaller water clusters (4-6 molecules) ...
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How to break down soap and detergents?

I am building a greywater harvesting system. It is a 3-stage system: The 1st stage breaks down soap and detergents. The 2nd stage filters the water. The 3rd stage pumps water out of system. What ...
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Removing Tungsten Trioxide from Tungsten Electrode

I need a very sharp tungsten electrode, and I think radial electrochemical etching with sodium hydroxide is the way to go. The problem therein (I think) is that the etching will cause an oxide layer ...
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Calculating total volume mixing NaCl and water

I'm (as a non chemist) trying to calculate the the volume of a NaCl solution. The problem is that I know the volume of water prior to mixing in NaCl, but I want to know the volume of the solution ...
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Chemistry Behind TMOS Aerogel

I have found out how to make silica aerogel. Currently, the solution that I need to create to make the gel requires tetramethyl orthosilicate or TMOS. Furthermore, the procedure requires me to make ...
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Hydrogen Peroxide Heat of Dilution

Based on some data here, I am getting the heat of dilution of 100% $\ce{H2O2}$ as approx. 1100 cal/mole. That's about 4.6 kJ/mol if I did my math right. Is this a correct value? Seems too low to ...
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Poor aqueous solubility of chloroazodin

Below is the structure of chloroazodin: Why is chloroazodin poorly soluble in water? It has multiple amine and imine nitrogens, all of which appear to be available for hydrogen bonding, and thus it ...
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Can a brine water electrolysis be looped?

Electrolysis of brine yields hydrogen and chlorine gases and aqueous $\ce{NaOH}$. So is it possible to combine the gases to form $\ce{HCl}$ gas, and mix it back with the aqueous $\ce{NaOH}$, so it ...
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Is it appropriate to approximate solute particles in a dilute solution as an ideal gas?

I was studying osmosis and I came across the formula for osmotic pressure. I decided to see the derivation for osmotic pressure in a dilute solution. The derivation involved an equation involving the ...
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Cleaning a stubborn Electrospray residue

I have an electrospray ionization capillary tip that sprays into a chamber that contains some circuit boards. An aqueous CsI sample is apparently causing a white residue to build up on these boards ...
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Mechanism for removal of pesticides from fruit by sodium bicarbonate

When Googling around for methods to remove pesticides from fruits and vegetables, a study commonly referred to from some news sites (e.g. here and here ) is one where soaking apples in a sodium ...
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Non-hydrate forming salts?

Are there any water-soluble salts that don't form hydrates? Hydration seems very thermodynamically favorable, as evidenced by its abundance. It also makes sense since the solvation and hydration ...
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Varying data about solubility of sodium acetate trihydrate

I recently looked up the solubility of sodium acetate trihydrate in water at 20°C and found surprisingly diverse values such as: 613g/l (GESTIS-Stoffdatenbank) 762g/l (TU Freiberg) 1250g/l (applichem, ...
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Should the concentrations in weight % of the components of a solution always add up to 100%?

There's a paper with this statement of a alkaline solution: Nanostructured CuO films were formed by immersing the cleaned tabs into a hot $(\pu{96 \pm 3 ^\circ C})$ alkaline solution composed of $\...
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What determines the maximum size of salt crystals as grown in flux growth?

Like many other children, I grew single crystal salt crystals in a salt solution. This is a common and fun experiment for children. However, with both this experiment, and with flux growth methods ...
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Why does soapy dishwater lose soapiness over time?

I wash dishes by making a concentrated solution of dishsoap (eg dawn) and water. Sometimes I'm lazy and forget to wash the container containing the soap solution, and it sits on the counter overnight....
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Best way to dissolve/emulsify beeswax and carnauba wax in water-based solution

What I can use to dissolve beeswax and carnauba wax and keep it in an aqueous solution? I do not want to use ethanol or acetone as they are too harsh. I am adding about $\pu{5\%}$ wax to a $\pu{16oz}$...
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How fast does atmospheric carbon dioxide dissolve into strongly basic solution?

I'm conducting some pH measurements with solutions containing NaOH and I'm a bit concerned that carbon dioxide will dissolve and affect my measurements by lowering the pH according to the reaction: $$\...
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Narrow range of pH for the formation of polyoxometalate clusters

The molybdate ion in aqueous solutions, speciates as clusters known as polyoxometalates (POMs) when it is acidified, but these clusters only aggregate in a very narrow pH range "polymeric range" in ...
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Vacuum filtration: will Polymer elements interfere with the vacuum?

I am doing an experiment with vacuum filtration, where a Nylon filter is used to create a membrane (marked in pink in the picture attached). When I use the membrane, it frequently breaks in the ...
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Extimating the repartition of water between hygroscopic compounds

Sulfuric acid is sometimes used as a drying agent. According to literature, one possible application is, for instance, in the drying of bromine. Some questions came to my mind: which concentration ...
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Why do fluoride ions “win” over thiocyanate ions in a solution with iron ions?

When you mix aqueous iron(III) nitrate and potassium thiocyanate together you get a red solution. Then if you add sodium fluoride, the red colour disappears. This is basically because the $\ce{Fe(...
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550 views

How does increasing ionic strength affect the pH of solution?

I'm having trouble interpreting the data for an experiment. With increasing ionic strength, I found lower solubility but also lower pH of the solution. What is the effect of the ionic strength on the ...
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Chemical theory, formula(s) that predict final *volume* of a solution?

I asked this question a couple years back regarding the volume of a mixture being less than the volume of the original solute and solvent, but this question asks if there is theory and/or formulation ...
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40 views

Ionic emission spectrum contamination

Imagine that I am trying to identify the presence of ions from among the metals $\ce {Li,Na,K,Ca,Sr, Ba}$ in some solution through their emission spectrum. By mistake the wire used to introduce ...
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Will bases typically precipitate silver atoms from silver ions?

In class I learnt that one can dissolve many substances using acid and that this can be predicted using standard electrode potentials. For example, $$\begin{align} \ce{Zn &-> Zn^{2+} + 2e^-} ...
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Why do some insoluble salts undergo slow chemical reaction instead of dissociation in water?

$$\ce{PbCl2 + H2O ->[\Delta] Pb(OH)Cl + HCl}\tag{1}$$ $$\ce{2ZnCO3 + H2O ->[\Delta] Zn2(OH)2CO3 + CO2}\tag{2}$$ $$\ce{2NiS + 2H2O → Ni2(OH)2S + H2S}\tag{3}$$ $$\ce{Hg2SO4 + H2O → HgO + Hg + ...
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Measuring the effect of increasing salinty on the concentration of Dissolved oxygen

I want to investigate the effect of increasing salinity on the concentration of dissolved oxygen, in a water sample being distilled water. Would that work? My concern is, that since its not a true ...
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Why is silver chromate red?

Copper(II) ions are blue and chromate(VI) ions are yellow therefore copper(II) chromate(VI) would turn out to be green because it's a mixture of blue and yellow. In the same way, silver ions are ...
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Do filter-specific dyes exist? Equivalently, do dye-specific filters exist?

Apologies if this isn't chemistry enough for chemistry.se. I'm happy to go elsewhere if there are suggestions. Blue + Red = Purple is arbitrary here. If any different colors might make this more ...
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Difference in color between the chromate and permanganate ions

As the title states, I'm wondering why the $\ce{[CrO4]^2-}$ and $\ce{[MnO4]-}$ ions display different colors in solution. Both of the metal ions have a $\mathrm{d}^0$ electron configuration, have the ...
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Alternative to water as solvent for lithium metaborate?

I want to prepare a sample of lithium metaborate ($\ce{LiBO2}$) and need to dissolve it for this purpose. The only solvents I found so far are water and ethanol. In ethanol, one cannot dissolve ...
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If both nitric acid and nitrate ion are stabilised through resonance, what makes the nitrate ion more stable in aqueous medium?

If both nitric acid and nitrate ion are stabilised through resonance, what makes the nitrate ion more stable in aqueous medium? Can the same argument be applied to nitrous acid and nitrite ion in ...
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Preparing CdSe electrodeposition bath

What is the best way of preparing an aqueous solution containing 5 mM $\ce{CdSO4}$, 1 mM $\ce{SeO2}$, 0.5 M $\ce{Na2SO4}$ and adjusting pH to 3 by adding 0.5 M $\ce{H2SO4}$? What is the ...
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Isoelectric point pH, mV, for a metal oxide nanopowder

I'm trying to make a solution of $\ce{TiO2}$ that will coat stuff in as dense a monolayer as possible. To do so, I'm using nano sized $\ce{TiO}$ particles and trying to get them to get as close to ...
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Maintaining a 40% CO₂ aqueous environment?

I wish to grow algae in a 40% $\ce{CO2}$ (water under air with 40% $\ce{CO2}$ content) aqueous environment. Simple DIY methods are available, but they are generally unreliable (For more info on DIY ...
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How do I go about either finding or calculating Aluminum-Oxalate salt solubility values in aqueous medium?

Water would contain other salts which may complicate things a bit. But finding out the Aluminum-Oxalate salts solubility values in pure water would be a good indicator already. It's for temperatures ...
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Over time what happens to soluble liquids with different densities

I have a case with two liquids: Water and another chemical which is miscible in water. The chemical has a density of 800 g/l so it's 20% less dense than water. Initially the chemical was mixed with ...
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Do TDS meters measure HCO₃⁻/CO₃²⁻?

I am trying to add $\pu{2 g}$ of $\ce{KHCO3}$ to $\pu{20 L}$ of RO water $(\mathrm{pH} = 5.2)$ which theoretically it will add $$ \begin{array}{lr} \hline \ce{K+} &\pu{10.32 ppm} \\ \ce{HCO3-} &...
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Qualitative analysis of iron(III) salt

Why will $\ce{Fe^3+}$ give brown ring test? In my textbook it was given that ferric ion gives brown ring too. I am confused, if ferric ion is already present, then what will reduce nitrate ion to ...
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how can I predict the rate of water ions precipitation on a surface?

Consider a titanium pot that contains 1kg water with the following ions: $[Ca^{2+}]=22000$ ppm, $[Mg^{2+}]=1500$ ppm,$[Sr^{2+}]=791$ ppm,$[Na^{1+}]=48000$ ppm,$[Cl^{1-}]=120000$ ppm,$[SO_4^{2-}]=...
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What causes the turbidity when preparing Fenton's reagent?

New guy, please be gentle. I might ask questions not according to conventions, I am not a chemist nor do I study chemistry. Feel free to adapt the question and the tagging. I am preparing a solution ...
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How to make rheoscopic fluid using glycol stearate flakes

Rheoscopic fluid can be made by adding mica powder to water. I read that mica powder can settle and condense after sitting around for a long time. So I want to use glycol stearate flakes instead. ...
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Dependence of Osmotic Effects on Particle Size

van't Hof's equation for osmotic pressure is derived with the assumption, among others, that the particle size of the solute is comparable to the particles size of the solvent. It holds well so long ...