Questions tagged [aqueous-solution]

For questions relating to compounds dissolved in water and resulting reactions and acid-base equilibria.

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1answer
74 views

Is it possible for a liquid chemical to have a pH value lower than its aqueous solution?

During the QC check of one of the products that we make as a company, the product had a $\mathrm{pH}$ of $10.44$ on one $\mathrm{pH}$ meter and $10.20$ on the other. (The product is a liquid, so it's ...
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Calcium sulfate soluble in water

In the volumetric estimation of calcium in a given solution as calcium oxalate. We convert the calcium oxalate to oxalic acid by dissolving the former in hot (~70 °C) 2 N sulfuric acid solution. This ...
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2answers
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Mass of salt required to make a 1.2 g/ml solution

I would like to make an NaCl and water solution with a density of 1.2 g/ml. How would you calculate the grams of NaCl required to make a 1000 ml solution? I have used density of mixture = (mass NaCl +...
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1answer
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The stability of the cupric and cuprous ions [duplicate]

My teacher told me that $\ce{Cu^2+}$ is more stable than $\ce{Cu+}$ in solution, but why? I think $\ce{Cu+}$ is $\ce{[Ar] 3d^10 }$ ,$\ce{Cu^2+}$ is $\ce{[Ar] 3d^9}$, why is $\ce{Cu^2+}$ more stable ...
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Why does final pH value of buffer solution after addition of acid not depend on amount added?

I'm brushing up and the example in my book is against my intuition. A buffer solution contains 1.0 mol/L acetic acid and 1.0 mol/L sodium acetate. The solution is at pH = pKa = 4.75. What's the ...
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1answer
7k views

How to figure out which substance has the highest osmotic pressure? [closed]

In preparing for an exam and I'm trying to solve the following question. I'm clueless. What should I do? Which of the following water solutions has the highest osmotic pressure? \begin{align} \...
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1answer
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What happens to potassium if potassium permanganate is reduced in a redox reaction? How can I identify spectator ions?

I'm trying to get a fool-proof way of finding the products of a redox reaction. I can do both the oxidation and reduction the half reactions. For example in the potassium permanganate with hydrogen ...
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1answer
87 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 1,5l. ...
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1answer
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How does increasing the ionic strength of an aqueous solution decrease the activity coefficient?

Activity is a new concept for me, and I am having a little bit of trouble understanding it. For the equation: $$\ce{aA + bB<=>cC + dD}$$ $$K_c= \frac{[\ce{A}]^a[\ce{B}]^b}{[\ce{C}]^c[\ce{D}]^...
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Does adding mass to a liquid (not water) increase the volume

The Question sounds stupid but i have a legit problem I mixed 1000 mL coconut water and 225 g of agar-agar to make a coconut water [CW] agar. It gave me more than 1000 ml. the medium went beyond the ...
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1answer
245 views

Does a weak buffer solution still maintain a mostly steady pH if the acid or base load it has to buffer is small?

I need to buffer the $\mathrm{pH}$ of a solution to $3.0$ using a citrate buffer. I found a recipe to make a buffer solution that would use $82\%$ of $0.1\,\mathrm M$ citric acid (monohydrate) and $...
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How does salt concentration affect corrosion rate of iron?

I have conducted an experiment where I test the affect of $\ce{NaCl}$ concentration on corrosion rate of iron. I did this in an environment were all of the iron was submerged in water and the water ...
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1answer
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What's the difference between aqueous NaOH and dilute NaOH?

Dilute $\ce{NaOH}$ can be prepared by adding a suitable amount of concentrated $\ce{NaOH}$. What's the difference between "dilute $\ce{NaOH}$" and "aqueous $\ce{NaOH}$"?
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Would sodium salicylate dissolve in HCl?

I've been searching around the web and the consensus seems to be sodium salicylate dissolves poorly in HCl because it would form salicylic acid. However, I don't understand why forming salicylic acid ...
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Why does phosphoric acid mask the colour of iron(III) complex in water?

In the redox titration of iron(III) with permanganate or dichromate, we use phosphoric(V) acid to "mask" the color of iron(III) because it interferes with the end point color change. What's the ...
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1answer
440 views

How to predict precipitate upon evaporation from calcium ions and either chloride, carbonate, or nitrate counterions?

An aqueous solution containing $\ce{Ca^2+}$, $\ce{Cl^-}$, $\ce{CO3^2-}$, and $\ce{NO3^-}$ is allowed to evaporate. Which compound will precipitate first? The correct answer is $\ce{CaCO3}$. I had ...
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394 views

Liquid that looks like smoke when bottled?

I am making a gift that will consist of a liquid in a sealed bottle. I want the liquid to have a magical appearance. Something like the appearance of smoke - varying opacity from almost clear to ...
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1answer
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Why is the enthalpy of solution for NaCl 3.88 and not 4.1 kJ/mol?

Based on Hess' law, the molar enthalpy of solution is equal to the sum of the enthalpies of formation of products minus reactants. In the case of dissolving table salt ($\ce{NaCl}$) in water, those ...
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1answer
133 views

Can I use fluorescence microscopy with a solution of hydrogen peroxide?

I want to use microspheres which have been dyed with a fluorescent dye for fluorescence microscopy in a solution that has a 1-5% concentration of hydrogen peroxide. Is this possible or will the ...
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Dissolve Silver Oxide

I was looking at how to dissolve silver oxide (in a solvent). I know that monovalent silver oxide will not dissolve in water, but are there any solutions in which monovalent silver oxide will dissolve?...
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NaOH to stabilize aqueous NaCN

This patent notes in passing: It may be necessary to add $\ce{NaOH}$ to stabilize aqueous $\ce{NaCN}$. Anyone skilled in the art would know the amount of $\ce{NaOH}$ to add. Obviously I'm not ...
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1answer
514 views

Electrolysis of water for demonstration: ideal electrolyte for safety, stability, conductivity, and ease of maintenance

I'm developing a system for educational purposes where electrolysis of water takes place. The aim is to practically show how electrical energy can be converted to mechanical, by electrolyzing water, ...
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1answer
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What is the proper way to prepare a solution from hydrate?

I am following a protocol that requires me to prepare $10~ \mathrm{mL}$ $\mathrm{1~M}~ \ce{Ca(NO3)2}$. However, there is only $\ce{Ca(NO3)2*4H2O}$ in the lab. Originally I thought that all I have to ...
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1answer
386 views

Does the salt in the ocean act as a binding agent on sand?

When I walk on the beach, there appears to be an upper layer of the sand that is 'crusty'. This appears to be the opposite of what you see in sand in a dessert setting, where the individual ...
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570 views

Why is water's IR spectra indistinguishable from the IR spectra of a solution of glucose in water?

Anhydrous glucose has an absorption spectra (glucose IR spectra) that is quite different from the spectra of water (Liq. water absorption spectra). However, when a solution of glucose is prepared in ...
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1answer
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Why do displacement reactions occur?

Suppose we have a compound, say copper sulfate. I know that sulfate is a poly-atomic ion, having valency 2. And, in this case, copper also has valency 2. So, to fullfill their 'octet' requirements, ...
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1answer
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How can I make a fairly saturated copper (II) sulfate solution by heating?

I have an investigation to do for my chemistry class. I'm looking at copper complexes and using ammonia to create a precipitate in the copper (II) sulfate solution, then redissolving the precipitate ...
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2answers
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Is Hydrolysis same as dissolution?

I have book that contains the following paragraph: Due to high dielectric constant, it (water) has a very strong hydrating tendency. It dissolves many ionic compounds. However, certain covalent and ...
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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 does CO2 lowers the pH of water below 7?

Ok so I understand that having a pH below 7 is considered to be acidic and I also understand that part of the definition of an acid is that it gives off H+ when dissolved in water(even though not all ...
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What happens to the bleach after mopping?

At home, I clean the tiled floors by mopping with highly diluted bleach. After mopping, I let the floor dry. What happens to the acid in the bleach? Will it crystallize on the floor, stay there ...
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How can bromine water be called a solution?

Bromine water is a reagent which is used to test for unsaturation in organic compound. It is $2.8~\%$ bromine in water according to Wikipedia. But how is it made? This link describes the procedure ...
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Solubility of carbon dioxide in 1M sodium hydroxide solution?

I know that carbon dioxide is soluble and forms carbonic acid, but exactly how is solubility measured? How soluble is carbon dioxide in a 1M solution of sodium hydroxide?
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1answer
181 views

Writing equilibrium expressions with aqueous species

If we have the reaction: $$\ce{A +BC_{(aq)} <=> D}$$ where $\ce{A}$ and $\ce{D}$ are generic compounds (neither is pure solid nor pure liquid) and $\ce{BC}$ is an ionic compound dissociated in ...
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1answer
666 views

Dissociation of silver chloride in a solution

When silver chloride is exposed to light it can dissociate to silver metal and atomic chlorine. It might be a silly question, but could the chlorine go back into the solution as chloride ions ? if so ...
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342 views

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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1answer
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Why aren't the copper(II) ions in CuSO4 precipitated by hydroxide ions from water?

From my own experience and literature, I know that $\ce{CuSO4}$ is well soluble in water and dissociates into $\ce{Cu^2+}$ and $\ce{SO4^2-}$. $\ce{Cu(OH)2}$, however, is not: $K_\mathrm{sp} = 2 \cdot ...
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1answer
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Precipitation with NaI

I dissolved $\ce{[Pt(NH3)4](NO3)2}$ in water then I added small amount of $\ce{NaI}$ ($1~\mathrm{M}$) to it. Precipitation occurred. I want to know what happened?
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What determines whether a double displacement reaction will occur?

In normal displacement reactions, reactivity plays a large role and sometimes the reaction doesn't even happen. So is there anything limiting double displacement reactions? For example $\ce{2KI + Pb(...
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Solubility involving precipitation

Question How do I found out how much $\ce{AgNO3}$ can be dissolved in 1 liter of solvent without precipitation of $\ce{AgCl}$. Solvent has $$M_{\ce{\,Cl-}} = 0.1\,{\rm M}\\M_{\ce{\,NH3}} = {\rm 1....
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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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370 views

Separate Dextrose & Caffeine in water?

Can a dextrose / caffeine powder be (mostly) separated by dissolving in water then filtering the water? Dextrose is readily soluble in water (1-10 parts solvent to 1 part solute). Caffeine anhydrous ...
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1answer
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How to minimise solution concentration changes due to evaporation?

Lets say I have a precise solution, and would like to store it long term (up to two years) with as little as possible change in concentration. The volume is 10-100ml. What container should I choose? ...
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1answer
788 views

Predicting pH of an acidic salt of an weak acid and weak base

Suppose we want to calculate pH of an $\ce{NH4HCO3}$ solution of known concentration. Now, $\ce{NH4+}$ will be hydrolised to give $\ce{H+}$ ions. Some $\ce{HCO3-}$ ions will be converted to (i) $\ce{...
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2answers
832 views

Common Ion Effect Calculations

Given a solution with a $\ce{S^{2-}}$ (sulfide ion) concentration of $2.76 \times 10^{-15}$ mol per litre, and $K_s(\ce{FeS})=4.90 \times 10^{-18}$, calculate the solubility of $\ce{FeS}$ in this ...
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1answer
2k views

Acidic and alkaline salt solutions: why do some salt form acid/bases while others don't [closed]

I have a question regarding salts and their solutions. How come some salts, like sodium carbonate and ammonium chloride, produce acids/bases when dissolved in water? Moreover, how can you predict ...
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109 views

Different ion effect

I need to have the highest concentration of (bi)carbonate ions in a water solution. Thus far, my only idea was to use Potassium Bicarbonate (safe and cheap) as it has the highest solubility but it ...
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1answer
377 views

Does carbonated water change over the course of several days, or was my container leaky?

I have a Klean Kanteen flip-top growler, allegedly leakproof at up to 35psi of pressure, that I filled with some freshly-carbonated water 4 days ago — just to see how long it would last. I used a Soda ...
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0answers
382 views

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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2answers
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Does H2CO3 exist in solution?

When $\ce{CO2}$ reacts with water, it supposedly forms $\ce{H2CO3}$, which is the aqueous form of $\ce{CO2}$. But it is hard to isolate, but its $K_\mathrm{a}$ value is pretty low (on the order of $10^...

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