# Questions tagged [aqueous-solution]

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

752 questions
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### Using cryptands to make a negatively-charged solution?

In our discussion group, my friend mentioned that metal cations can be separated from other cations in solution using cryptands. After addition of the cryptands to the solution of the cations, ...
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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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### Potentiometric determination of fluoride

We did an experiment of potentiometric determination of fluoride ions. In several beakers we added several concentrations of NaF solutions and then we added water. We calculated with the electrode the ...
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### Molality of the solution prepared from a hydrated salt

A solution is made up by dissolving $\pu{13.8 g}$ $\ce{Na2CO3 · 10 H2O}$ in $\pu{103.5 g}$ of water. What is the molality of $\ce{Na2CO3}$ in this solution? I can't solve it. I tried converting to ...
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### How to dissolve white dextrin in water?

Dextrin is labelled as highly soluble in water. I have white dextrin (analytical from Sigma Aldrich). When I mix it in water, no matter how long I stir and how little dextrin I put, I get a suspension....
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### Weight of sodium acetate required to get to certain pH

How many grams of $\ce{CH3COONa}$ we need to dissolve in $\pu{2.50 L}$ of water to get a solution with $\mathrm{pH} = 9.00$? Given $K_\mathrm{a}(\ce{CH3COOH}) = 1.75\cdot 10^{-5}$ Like solving a ...
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### Does acid and base react directly, or do they react first with water?

If an acid $\ce{AH}$ reacts with a base $\ce{B}$ in aqueous solution, in textbook they write $$\ce{AH + B -> A- + BH+}\label{rxn:1}\tag{1}$$ But first I add acid to water and then base, so why ...
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### Finding equilibrium constant from solubility product constant

Given $$\ce{CuI(s) <=> Cu+(aq) + I-(aq)}\, ;\qquad K_\mathrm{sp} = 1.2 \cdot 10^{-12}$$ write a reasonable chemical reaction that describes the decomposition of $\ce{CuI2}$ in aqueous ...
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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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### Electrolysis of diluted sulfuric acid

My teacher told me that electrolysis of dil. $\ce{H2SO4}$ (concentration below $50\%$) using inert electrodes results in gradual increase of the concentration of $\ce{H2SO4}$. I can't seem to figure ...
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### USNCO question - Finding pH of salt solution from pKa of its parent acid

The question from 2017 USNCO is as below: What is the $\mathrm{pH}$ of a $\pu{0.25 M}$ solution of $\ce{NaCN}$? (The $\mathrm{p}K_\mathrm{a}$ of $\ce{HCN}$ is $9.21$.) (A) $4.91$ (B) $8.61$ ...
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### How do you experimentally calculate the ionization constant of the carbonate ion?

Given sodium hydrogen carbonate, $\ce{NaHCO3}$, as well as hydrochloric acid, $\ce{HCl}$, how would you experimentally determine the ionization constant for the carbonate ion, $\ce{HCO3-}$? By ...
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### Solubility of Calcium Oxalate in Aqueous Alcohol?

In searching through the literature for the solubility of calcium oxalate, I came across this post https://www.researchgate.net/post/Are_there_any_organic_inorganic_solvents_for_dissolving_Ca-oxalate ...
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### How much additional hydrochloric acid should be added to arrive at ‘excess acid’?

I am an IB student. And I am trying to find the mass percentage of $\ce{NaHCO3}$ in antacid. I am dissolving the antacid in $\pu{0.1 M}$ $\ce{HCl}$ solution. So, first of all I conducted some ...
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### Electrolysis of NaCl

Given a concentrated solution of $\ce{NaCl}$ in $\ce{H2O}$ produces $\ce{H2}$ and $\ce{Cl2}$. How many liters of $\ce{Cl2}$ does it produce after $3$ hours with a current of $\pu{4 A}$? I used the ...
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### In the blue bottle experiment, will it eventually be “used up” after repeated use?

The blue bottle experiment is a bottle half full of a colorless solution (dextrose, KOH, and methylene blue, in the version that I saw) and air that, when shaken, turns blue through the methylene blue ...
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### Quantity of water in a redox problem

$\pu{76 g}$ of $\ce{FeSO4}$ are oxidized by $\pu{0.04 M}$ solution of $\ce{KMnO4}$ in presence of $80\%$ $\ce{H2SO4}$. What quantity of water must be added to the final solution of $\ce{Fe2(SO4)3}$ ...
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### What visual observations can confirm that a reactant is the limiting reagent?

I have this lab question for the lab called Copper Collection Stoichiometry, where we choose an amount of the limiting reagent (iron) for a reaction between copper (II) sulfate and iron. We are to ...
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### Converting mass percentage of a solution into its density? [closed]

Is there a way of converting mass percentage of a solution to obtain its density? (With mass percentage been given and the compounds which are mixed to form the binary solution)
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### Why do the Ions Swap in double displacement?

I'm curious but in a double displacement reaction I know that the anions are swapped around and normally a precipitate is formed, but why do the ions swap? Has it got something to do with electrical ...
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### Why are indicators used only in the form of dilute solutions?

Why are indicators used only in the form of dilute solutions? I get that indicators are a form of weak acids themselves, and the extent of their dissociation varies with the pH of the solution they ...
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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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### So, is baking soda actually a strong base? [duplicate]

Based on my recent thoughts, when baking soda ($\ce{NaHCO3}$) is dissolved in water, the following hydrolysis reaction occurs: $$\ce{NaHCO3 + H2O <=> NaOH + H2CO3}$$ However, \ce{H2CO3 -> ...
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### Is the crystallization process of aqueous solutions of substances such as lithium chloride endothermic?

$\ce{LiCl}$ has an enthalpy of solution of $\pu{-37.1 kJ/mol}$, so its dissolution process is exothermic. Does this mean that it's crystallization process is exothermic? I'm asking since I've looked ...
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### How to calculate Debye length of a 2-1 electrolyte

I am given the Debye length to be 10nm for 0.001M KCl at 298K. I want to know its Debye length in 0.01M CaCl2. How can this be calculated? I know that for 1-1, the Debye length is inveresely ...
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### How does adding sodium chloride to a solution of copper sulfate change the equilibrium? [closed]

In school we had a lesson about chemical equilibrium. We performed an experiment: in two tubes we poured $\pu{5 mL}$ of $\ce{H2O}$ and placed $\ce{CuSO4}$, the concentration of the $\ce{CuSO4}$ should ...
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### 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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### Cationic Detergent with no odor [closed]

I am looking for a cationic detergent for a project. Unfortunately most ( or all?) cationic detergents are quaternary ammonium that smell like rotten fish or even worse The product I am working on ...
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### How to calculate the concentration of the elements after dissolution of iron(III) chloride?

I was presented with the following problem: In the laboratory you dissolve $\pu{24.7 g}$ of iron(III) chloride in a volumetric flask in water to a total volume of $\pu{375 ml}$. What is ...
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### What are the dangers associated with a copper sulfate CuSO4 + Water H2O solution aprox 5 gallons at room temperature in a room with no ventilation.

Will there be hazardous gases in the room? is the evaporation of this solution harmful in any way to animals or humans?
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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 is the specific gravity of 0.9 % saline 1.0046?

Medical Normal Saline (0.9% Saline) contains 9 g of salt dissolved in 1000ml of water. Hence a litre of NS should weigh 1.009 kg. Hence its specific gravity should be 1.009, but it’s only 1.0046. (I'...
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### Solubility of Alkali Metal Chlorides

Why does Potassium Chloride less soluble than Sodium Chloride in water, isn't it supposed to be other way round? Since Potassium Chloride would be more ionic than Sodium Chloride?
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### Why isn't the hydroxyl group of citric acid deprotonated while the carboxyl groups are?

My AP chemistry book "Chemistry: the Central Science 12th edition" says that one molecule of citric acid generates 3 H+(aq) ions when dissolved in water. Looking at the structural formula: There are ...
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### Can a used-up buffer solution be used again in the other direction?

Suppose a strong base is added into an acidic buffer (such as acetic acid buffer) up to the endpoint. This means that the acetic acid molecules neutralize the hydroxide ions to the point that the ...