Questions tagged [aqueous-solution]
For questions relating to compounds dissolved in water and resulting reactions and acid-base equilibria.
1,240
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How to calculate the pH value of a Carbonate solution?
I read the similar questions suggested when submitting my question but they didn't help me How can one calculate the pH of a solution? How to calculate pH of the Na2CO3 solution given ambiguous Ka ...
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Are solubility product (Ksp) and dissociation constant (Kd) unrelated? [closed]
Dissociation constant can be calculated from the Gibb's energy released by the dissociation, but as best I can tell, there's no way to determine solubility from dissociation constant, as things can ...
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Would a container made of sugar eventually dissolve if filled with a sugar-saturated solution of water?
Suppose you had a bottle made of sugar glass, and filled it with water that was already saturated with sugar.
I know that with a fully saturated solution of sugar in water, no additional sugar can ...
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Why is it recommended to not store commercial sodium silicate solutions in direct sunlight, what are the effects of doing so and can it be modelled?
I regularly purchase aqueous sodium silicate solutions from commercial providers for my studies and note that a storage recommendation for all different grades (i.e. differing $\ce{SiO2 / Na2O}$ ...
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Synthetic resin method to remove permanent hardness of water [closed]
Why is $\ce{R-SO3H}$ first treated with NaCl and then the RNa form i.e., the sodium form of resin is used for treating hard water? Why cannot we directly treat hard water with $\ce{R-SO3H}$? What is ...
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Calculate the concentration of HF in aqueous solution of NH4F and NH4HF2 mixture
There is a similar question on this site, but here i have a mixture.
I have a mixture of NH4F (35% weight) and NH4HF2 (8% weight) in water. How do I calculate the weight % expressed in HF? or the ...
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Notation for spectral density in experimental community
In an open quantum system setup where the system is coupled to infinite harmonic oscillators as bath (as in the Caldeira leggett model, for example), through the Hamiltonian,
$$H = \frac{\hat{p}^2}{2m}...
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Find the added volume of HCl so that the ions separate
Suppose we have a 10mL solution that contains 0.02M $\ce{Ag^+}$ and 0.04M $\ce{Ba^{2+}}$. a) Find the necessary volume to be added of $\ce{HCl}$ to separate all the silver. (Assume to be separated if ...
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Is calcium carbonate a Brønsted–Lowry base, a Lewis base, or both? [closed]
What type of base would $\ce{CaCO3}$ be in the following example:
$$\ce{CaCO3 + H2SO4 -> CaSO4 + CO2 + H2O}?$$
My understanding is that calcium carbonate cannot be a Brønsted–Lowry base because ...
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Why is 10 times phosphate-buffered saline more acidic (~6.9) than 1 time phosphate-buffered saline (~7.4)? [closed]
Recently, I've been told that similar pH shift (of about 0.5 units) was observed with 20 times NPS solution as well.
In case of NPS the authors provide the following recipe for the 20 times solution:
...
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Is it always necessary to boil off H2S(g) to test for group III cations in qualitative analysis?
When a sample contains $\ce{Al^3+}$ ions (group-III), to test for its presence, before adding NH4Cl/NH3 solution do we need to boil off acidic H2S added earlier to check for the presence of group-ii ...
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Determining the concentration of a very small sample of sulfuric acid
How can we determine the concentration of sulfuric acid in a very small sample?
We are working on a “mechanical” process that transports a very small amount of sulfuric acid to an instrument and we ...
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How to find the amount of ions from the dissociation of a weak acid? [duplicate]
Someone asked me this question,"How many ions are formed during the dissociation of 500 molecules of carbonic acid, if it dissociates in the first degree by 20%, and in the second degree by 1%?&...
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How to balance iodometric equations using ion electron method? [duplicate]
I found out the reductant, oxidant, oxidation half reaction, reduction half reaction; balanced ions (adding $\ce{H2O},$ $\ce{H+},$ electrons) and charges:
$$\ce{K\overset{-1}{I} + \overset{+2}{Cu}SO4 -...
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Why doesn't hydroxide associate with water analogously to proton forming hydronium?
I'm a novice at chemistry. I've heard that an acid needs water to show its acidic properties, that's why nitric acid needs to be associated with water to show its acidic properties:
$$\ce{HNO3 + H2O &...
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Reaction of lead with acetic acid and hydrogen peroxide solution
My textbook says lead reacts with acetic acid when there is enough oxygen to oxidize lead:
$$\ce{2 Pb + O2 + 4 CH3COOH -> 2 Pb(CH3COO)2 + 2 H2O}$$
So, I added lead into mixed solution of acetic ...
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Why phenolphthalein is not completely neutralized in basic solutions? [closed]
Phenolphthalein $(\ce{HIn})$ is slightly acidic. Why doesn't it completely break down into $\ce{H+}$ and $\ce{In-}$ and also reacting with all of the $\ce{OH-}$ ion present, unlike $\ce{NaOH}$ and $\...
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Store Palladium Chloride in Solution
I have one gram of palladium chloride ($\ce{PdCl2}$) and I want to use very small quantities of it, in milligrams somewhere. It is not possible for me to get my hands on a scale that can measure that ...
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Reaction of hydrogen peroxide with acetic acid and potassium permanganate
I conducted an experiment where I mixed hydrogen peroxide $\ce{H2O2}$, acetic acid $\ce{CH3COOH}$ and potassium permanganate $\ce{KMnO4}$ under vigorous stirring. The reaction hasn't stopped after 15 ...
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Is lead iodide a strong electrolyte?
So, lead iodide is insoluble. I see conflicting answers online. Some say it's a weak electrolyte because it is insoluble, others say it is a strong electrolyte because it is an ionic compound and any ...
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Magnesium vs calcium vs barium ions from these 3 tests
How do I pick up the difference between barium, calcium, and magnesium ions? I had to do a quantitative analysis practical exam: I was given an aqueous solution of a salt, and when adding separately ...
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How does pH affect the rate that CaCO3 dissolves in freshwater?
It is my understanding that calcium carbonate dissolves faster in lower pH environments. I am interested to know how higher PH levels affect the rate of dissolution. So I have broken this question ...
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What will be the products of the reaction between a metal (i.e. zinc) and a solution containing two dilute acids i.e. HNO3 and H2SO4? [closed]
The metal is dipped into a beaker that has the two acids, sulphuric (VI) acid and nitric (V) acid in equal concentrations.
In my preliminary research, I found that there might be several possibilities....
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Why is there a decrease in the total volume when NaOH dissolves in water?
When a solute is added to a solvent, the volume of the solution should be equal to the sum of the individual volume of the solute and solvent (i.e total volume), right? But why is there a decrease in ...
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What is the significance of charge balancing when analysing system speciation (carbonate system given as an example)?
Following on from my previous question and accepted answer, How do I quantify the carbonate system and its pH speciation?, I also calculated a charge balance ($CB$) on the system where $z$ is the ...
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Why does the pH of very strong NaOH solutions not make sense? [duplicate]
I'm wondering why the pH of extreme alkaline solutions, such as the case with $\pu{10 M}$ $\ce{NaOH}$ does not make practical sense and I'm wondering why this is the case? Refer to my calculations ...
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Why do we call salts such as AgCl sparingly soluble?
Though we use the term practically insoluble for salts like $\ce{AgCl}$ in inorganic chemistry, we preferably call them "sparingly" soluble salts in physical chemistry seeing their tiny ...
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Solubility comparison for para-nitrophenol and phenol
During lecture with our chemistry teacher, he randomly asked us to compare solubility of phenol and p-nitrophenol, we expected p-nitrophenol to have greater solubility than phenol due to better dipole ...
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Does nitrous oxide decolorize potassium permanganate?
My teacher says that nitrous oxide can't form any complex with manganese in aqueous solution, so it can't be oxidised. However, shouldn't it get oxidised as it is present in the intermediate oxidation ...
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How to measure pottery glaze leaching?
I am looking for a way to know if glazes from pottery leach chemical compound in water.
Those are usually metal ions: cobalt, manganese, chrome, etc.
The procedure would be to place hot water in the ...
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How do I quantify the carbonate system and its pH speciation?
I did Environmental Water Chemistry as part of my undergraduate course where we quantified pH-speciation for the full carbonate system and I got it right according to my tutor. My speciation profile ...
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At constant solvent activity, do solution properties depend on identity of the solute?
When a substance is dissolved or mixed with water in high concentrations, the activity of water drops from 1 to a value that depends on the substance and its concentration. Is it correct to say that ...
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How the optical fibre pH microsensors work?
Just browsed through the chemical sensor products of the company, called PreSens (https://www.presens.de/products/ph/sensors) in order to look for a precise method to measure pH change in a ...
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amorphous silica (diatomaceous earth) dissolution and precipitation using household bleach or ammonia [closed]
I'm a layman not a chemist. My question is whether it's possible to dissolve amorphous silica in room temperature water mixed with a commonly available alkaline household product and then have it ...
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Electrical conductivity of a NaOH solution
We are doing a simple water electrolysis experiment but I have issues with the electrolyte solution.
Took 450ml of distilled water and slowly dissolved 50g of NaOH until heating ceased. If I'm not ...
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Hydrofluoric acid
At work we have a large tank that is comprised mostly of hydrofluoric acid, I don't know the dilution factor as I'm not the one making the bath, but I have a question, when emptying the bath we tried ...
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Do ion-exchange membranes *always* require ions to pass in both directions?
In an answer to this question, it was asserted that:
Student always tend to forget that a solution must remain electrically neutral by all means. If you want a certain ion to leave water, you must ...
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Is there a material that ions can pass through but water can’t?
I was wondering whether there is a material that can pass ions (such as the ions existing in seawater) but not water. I am aware that water molecules are smaller, so they can pass through some ...
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Variation of conductance of saturated aqueous solution with temperature
The following question was asked in JEE Mains 2020:
Let $C_{\ce{NaCl}}$ and $C_{\ce{BaSO4}}$ be the conductances (in S) measured for saturated aqueous solutions of $\ce{NaCl}$ and $\ce{BaSO4}$, ...
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Gouy-Chapman model
Recently I have been investigating the problem of a neutral solutions (with equal number of anions and cations) interacting with an infinite surface $z=0$ with electrostatic potential $\phi(z=0)=\...
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Transforming hydroxyl group to carboxylic acid in an aqueous environment
I am looking for a way of converting a hydroxyl group into a carboxyl group in an aqueous environment for eventual coupling to an amine. There seem to be plenty of ways of achieving this in various ...
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Details of what actually happens in cold sulfuric acid between 80 and 90%; what molecular changes cause the viscosity to skyrocket?
AChem's answer to Why does the graph of the electrical conductivity of sulfuric acid/water solutions have this knee in the ~85%-~92% range? includes this plot from Horace E. Darling in "...
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Why is my battery of galvanic cells not enough to power a lamp rated for a lower voltage than the battery provides?
I made a series of 12 galvanic cells with saltwater as an electrolyte and zinc and copper as electrodes. It produces 8.8 V, but it can't even light a 2.5 V bulb (the bulb can be lit by a 1.5 V source)....
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Purifying ferrous sulfate
For my wood staining experiments I have purchased 1 kilo of ferrous sulphate as a source of iron(II). It turned to be quite oxidised (yellowish) and the its solution is muddy yellow instead of green. ...
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How to find pH for acetate buffer?
Calculate the pH of the solution that results when $\pu{40.0 mL}$ of $\pu{0.100 M}$ $\ce{CH3COOH}$ is mixed with $\pu{30.0 mL}$ of $\pu{0.200 M}$ $\ce{NaCH3COO}.$ $K_\mathrm{a}(\ce{CH3COOH}) = \pu{1....
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How does CO2 'dissolve' in water (or blood)?
I'm trying to understand CO2 dissolved in blood, carbonic acid and the bicarbonate ion. I think of 'dissolving' as in NaCl dissociating into Na+ and Cl- ions sloshing around in water. CO2 isn't ...
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Why does copper(II) sulfate solution turn black on addition of excess sodium borohydride?
In my laboratory experiment, I was supposed to reduce copper(II) sulfate to copper by means of $\ce{NaBH4}$, an indication of which was supposed to be a colour change from blue (copper(II) sulfate) to ...
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Determining iron(III) content in mixture of iron(II) and iron(III) [closed]
Problem
Outline a plan of an experiment to determine the percentage of iron present as iron(III) in a solution containing $\ce{Fe^3+(aq)}$ and $\ce{Fe^2+(aq)}$ ions. You are provided with zinc, a ...
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What happens during a displacement reaction? [closed]
When Zn metal is added to a solution of Cu(II)SO4, Zinc displaces Cu to form ZnSO4 as Zn is more reactive than Cu. What I don't understand is how.
1- What I'm assuming is: Zn metal collides with [SO4]...
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How to remove oil/grease contaminant from an aqueous solution?
I have a solution of water and calcium nitrate that is contaminated with some sort of heavy petroleum oil, semi-solid at room temperature a bit like petroleum jelly, and a strong odor of very crude ...
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