Questions tagged [aqueous-solution]
For questions relating to compounds dissolved in water and resulting reactions and acid-base equilibria.
1,229
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Would having a greater H-bond donor count make a substance more readily enter a twig?
Yes, weird plant scientist asking weird plant questions...
Background:
I am looking at how the twigs of trees absorb water, a poorly understood means by which trees alleviate water stress. Of 4 ...
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4
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1
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542
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Possible technique for measuring pH in solutions
I would like to develop a device that measures pH in aqueous solutions. I'm not a chemist, but I have some basic knowledge about electrochemistry. So, I thought I could use two electrodes quite close ...
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Is there any equation to predict the salting out concentration of a polymer?
I have to roughly calculate the salting out concentration of a polymer with respect to NaOH.
Is there any method to calculate?
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0
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Plastic 15mL conical tube cap damaged after storing Tween20 for a long time
The tube is made of polypropylene (PP) while the cap is made of High Density Poly Ethylene (HDPE). We use it to store a few mL of 5% Tween20 (in PBS) under standard conditions and is exposed to ...
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4
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Drying salts with HCl solution
I'm following a protocol from some old literature (1962), and I want to make sure I'm being safe. It asks you to dissolve some salts in 150 mL water + 25 mL concentrated HCl, then evaporate to dryness ...
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50
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Can we add specific conductivities at any concentration?
Suppose we have specific conductivities of $\pu{0.1 M}$ $\ce{K+}$ and $\pu{0.1 M}$ $\ce{Cl-}$. Can we add their specific conductivities to get specific conductivity of $\pu{0.1 M}$ $\ce{KCl}$?
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60
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Proper, safe disposal of hydrated sodium polyacrylate mixed with (table) salt?
I have a bunch of hydrated sodium polyacrylate (about 25 grams + 5L of water) that has solidified into a gel, and I want to dispose of it.
I have read online that it is not good to dispose sodium ...
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40
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Separation of sodium acetate and calcium chloride
So basically i have seen that if i mixed calcium acetate and sodium chloride in a water solution it would give sodium acetate and calcium chloride. The problem is i need to extract that calcium ...
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48
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What is the name of the bond between oxygen atoms and Na+ ions when NaCl dissolves in water?
When NaCl (sodium chloride, table salt) dissolves in water, the NaCl molecules break apart. The hydrogen atoms form hydrogen bonds (I think?) with the Cl- ions. What is the name of the bond between ...
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2
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444
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Residue left after evaporation of a salt solution
When a salt solution is evaporated (bunsen burner, evaporating dish/beaker), for example CuSO4 aq, there will be residue left over, as with all salt solutions.
However, the common form of copper (II) ...
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4
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How does a silver chloride electrode (Ag/AgCl) convert the potential in aqueous solution to the wire?
I am aware of the redox chemistry that happens at the electrode surface, but I'm not sure how exactly a change in electrical potential in the solution would change the potential in the electrode?
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Solubility of SrF2 in aqueous solution of NaF
This might be really simple question but I have no idea how to proceed to solve such kind of question.
The solubility product of $\ce{SrF2}$ in water is $\pu{8E-10}$. Calculate its solubility in 0.1M ...
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2
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1
answer
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Reducing vaporization of concentrated hydrochloric acid solution
I have this bottle of hydrochloric acid solution. Although I do not know its concentration but I know it is quite concentrated. Every time I open it the fumes would get to all the places.
I have an ...
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Sodium Citrate / Sodium Phosphate Buffer Calculations
I'm trying to work through the calculations of a specific paper (linked here / below) but, my numbers are way off and I can't get them to match for the life of me. I need to make the same buffer but ...
2
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1
answer
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Equilibrium Solubility of CO2 in Aqueous Solution and its Dependence on H3O+ Concentration
The equilibrium solubility of $\ce{CO2}$ in an aqueous solution is given by three chemical reactions:
$$
\begin{align}
\ce{CO2(g) &<=> CO2(aq)}\label{rxn:R1}\tag{R1}\\
\ce{CO2(aq) + H2O &...
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1
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Are all salts completely dissociated in solution when put in smaller amounts than their molar solubility?
From what I understand, the solubility is given in terms of molar solubility (or $\pu{K_{sp}}$), from which it can be easily calculated). Indeed, the saturation point represents the maximum amount of ...
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1
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Scrubbing methanol and ethanol from a gaseous mixture
I have a gaseous mixture (air) at a temperature of approximately 30 degrees Celsius in which the following gases are present:
Oxygen 0 - 25%
Carbon Dioxide 0 - 20%
Methanol 0 - 100 ppm?
Ethanol 0 - ...
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2
answers
58
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Successive deprotonation - how far can it go?
It has been written that among the equilibria of the dissolution of $\ce{SO_2}$ in water, the dissociation of sulphur dioxide into $\ce{HSO_3^-(aq) + H_3O^+(aq)}$ is a complete dissociation. See the ...
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1
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How do I make a 6-mercapto-1-hexanol (MCH) aqueous working dilution?
I am using 6-mercapto-1-hexanol (MCH) as part of the immobilization procedure for forming a self-assembled DNA monolayer on a gold surface (see the first figure of this paper for a good visual ...
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1
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What is a suitable process to eliminate an excess of pyridine from an aqueous solution?
I have a reaction in which pyridin is used as a reagent in excess. The resulting product is water soluble and an anion. Pyridinium there will act as a counter ion. Normally, when the product is ...
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2
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Is the hydrolysis of a salt produced by neutralisation a secondary reaction? [closed]
I understand that in a solution, the salt created by a neutralisation reaction can react again with water molecules, which can further affect the pH. Is it correct to say that the hydrolysis of salts ...
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What is ionic reaction equation for reaction between carbon dioxide and limewater?
Write the ionic reaction equation for the reaction
\[\ce{Ca(OH)2(aq) + CO2(g) <=> CaCO3(s) + H2O(l)}.\]
I first wrote the complete ionic equation as such:
\[\ce{Ca^2+ + 2 OH^- + CO2 <=> ...
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6
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381
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Do hydration (as in "solvation") and "hydration" of salts refer to the same phenomenon?
I've come across two use cases of the word "hydration", presented to me as distinct topics:
Solvation is the process of reorganizing solvent and solute molecules into solvation complexes ...
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0
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Dissolution of portlandite, calcite/CaCo3 phase and C-S-H due to high pH
I would like to ask about the possibility of the partial dissolution, over curing time, of portlandite, CaCo3 and C-S-H phases due to high pH (12.5 - 13) of the lime-clay-water systems (lime-...
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2
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What is the inconsistency in calculating the differences in Na2O and NaOH in solids (v2)?
(Note that this question has been fully edited for clarity, SE help advised not to delete the question and post another).
Background:
I have a computer model in which I feed it input data from various ...
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1
answer
43
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Passing protons through cation-permeable membranes
Protons are attached to a water molecule (making hydronium) in acidic solutions. If a container was split through the middle with a cation-permeable but anion impermeable membrane and, say, HCl was ...
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1
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What's the pH of a solution knowing only pKa, mass and volume? (no molecular mass known)
Is it possible to calculate the pH of a given solution knowing only the pKa (but not the structure of the acid, i. e. its molecular mass), its mass and the volume of the solution? E. g. What is the pH ...
3
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1
answer
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When NaOH ionizes in water, does the OH– react with the water molecules or with the hydronium ions from the dissociation of water?
NaOH in water becomes $\ce{Na+}$ and $\ce{OH-}$ ions. If it's a Bronsted Lowry base then the $\ce{OH-}$ ions will take $\ce{H+}$. But FROM where exactly - from the water molecules or from the ...
0
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1
answer
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Why does the reaction of dissolution stop at an equilibrium point? [closed]
The formula for Gibbs free energy is $\Delta G=\Delta H-T\Delta S$.
If Gibbs free energy is negative, the reaction is spontaneous. This also applies to dissolution reactions.
However, we know that ...
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Is the process of volume decrease in NaOH solutions reversible during evaporation of water from the solution? [closed]
While preparing w/w 50% NaOH solution I noticed a decrease in solution volume (5-10mL) in a 2L volumetric flask, so I am wondering if there is an increase in water volume during the water evaporation ...
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0
answers
689
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Buffer solution of NaH2PO4 and Na2HPO4
We have this exercise without solutions
From a 0.2 M $\ce{NaH2PO4}$ solution and a 0.2 M $\ce{Na2HPO4}$ solution, a buffer
solution with pH = 6.8 is to be prepared. The total concentration of
$\ce{...
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2
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526
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Calculate the titer of a solution
I hope this is the right place to ask. We have this exercise without solution
One litre of diluted sodium hydroxide solution (c = 0.15mol/litre) is
to be prepared in the laboratory. The titer from ...
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0
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2
answers
115
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Electrode potential and likeliness to reduce/oxidize (electrolysis) [closed]
I'm a little confused about situations where multiple chemical compounds can be reduced/oxidized and the likelihood of this happening to one compound over the others, depending on the electrode ...
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1
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55
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What happens to a solute's potential energy during diffusion?
I was thinking, if you have a large amount of water, with an uneven solute concentration, diffusion will lead to an even concentration of solute throughout the solution.
Intuitively,that would mean ...
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2
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Should I give an endothermic reaction the exact energy it needs to occur or can I give it in parts?
I know this might be a silly question, but should I sustain the exact energy or more for the enthalpy of endothermic reaction to occur or can I give it in parts?
Let's say a certain reaction requires $...
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1
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What is the maximum number of silver(Ⅰ) ions in one litre of a 0.003 M sodium sulfide solution?
What is the maximum number of silver(Ⅰ) ions that can be present dissolved in one litre of a $\pu{0.003 M}$ $\ce{Na2S}$ solution?
According to my book, silver(I) reacts with sulfide producing $\ce{...
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3
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What is the precipitation reaction?
I asked my teacher if the reaction
$$\ce{(NH4)2CO3 (aq) + MgBr2 (aq) <=> MgCO3 (s) + 2(NH4)Br (aq)}$$
can be considered a displacement reaction. She answered that it was a precipitation reaction ...
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0
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Why is the precipitate formed after dissolving trimagnesium dicitrate anhydrate?
In my research I try to prepare trimagnesium dicitrate aqueous solution. Initially it stays clear, but after some time white insoluble precipitate is formed. Initial pH was about 4,5-5,0. If pH is ...
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Why might a prepared 1% solution of glucose take 2 hours to give maximum, stable reading on a glucometer?
I put 1.000g of glucose powder into a 1 L volumetric flask and filled the flask to the 1L line with room temperature distilled water.
I then inverted several times for 10 minutes to mix until there ...
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2
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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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2
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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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0
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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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114
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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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2
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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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4
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0
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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,
$$H = \frac{\hat{p}^2}{2m}...
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2
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2
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Find the added volume of HCl so that the ions separate
Suppose we have a 10mL solution that contains 0.02M $\ce{Ag^+}$ and 0.04M $\ce{Ba^{2+}}$. a) Find the necessary volume to be added of $\ce{HCl}$ to separate all the silver. (Assume to be separated if ...
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1
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Is calcium carbonate a Brønsted–Lowry base, a Lewis base, or both? [closed]
What type of base would $\ce{CaCO3}$ be in the following example:
$$\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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0
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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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