All Questions
Tagged with solutions aqueous-solution
202
questions
2
votes
2
answers
145
views
In an unsaturated solution, is the product of ions still equal to Ksp?
Suppose I have a solution of a sparingly soluble compound, and consider its solubility in g/L. If I have less g/L of solution than that amount, it means the solution is unsaturated, but what happens ...
- 67
1
vote
0
answers
75
views
What does it mean for a substance to be "sparingly soluble"?
I have trouble understanding what solubility means. Merriam-Webster defines it as follows:
1 the quality or state of being soluble
2 the amount of a substance that will dissolve in a given amount of ...
- 67
1
vote
0
answers
43
views
Increasing energy density for flow batteries with water based electrolyte?
Given a flow battery with a water based electrolyte, would it be possible to increase the energy density of battery by precipitating the redox active species from the anolyte and catholyte solutions? ...
-4
votes
1
answer
61
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Is it possible to make acids and bases in amphiprotic solvents other than water [closed]
In such solvents, could there be chemicals which could donate/accept protons, and if so could their solutions display acidic/basic properties?
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2
votes
4
answers
172
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How can the Kw of water be constant?
I know in neutral solution, $\ce{[H+]}= \ce{[OH-]}= \pu{1.0 x 10^-7}$.
However, let’s say I add an acid like HCl. This will increase $\ce{[H+]}$, therefore it’s no longer $\pu{1.0 x 10^-7}$, but is ...
- 41
2
votes
1
answer
86
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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
vote
2
answers
181
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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 ...
- 500
0
votes
1
answer
59
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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 ...
1
vote
0
answers
2k
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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{...
- 423
3
votes
2
answers
2k
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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 ...
- 423
1
vote
0
answers
69
views
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 ...
- 21
-5
votes
1
answer
59
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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:
...
- 111
4
votes
4
answers
244
views
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 ...
- 41
9
votes
3
answers
3k
views
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 ...
- 299
0
votes
0
answers
51
views
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 ...
- 1
4
votes
1
answer
366
views
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 $\ce{BaSO4}$, ...
- 476
2
votes
0
answers
109
views
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)=\...
- 121
1
vote
1
answer
208
views
What is the effect of adding another solute to the solubility of the initial solute?
Let's say we have a saturated salt solution with 35 g/100 mL NaCl in water. If we add another solute up to its saturation concentration, for example 182 g/100 ml sucrose (C12H22O11), what happens?
...
0
votes
0
answers
65
views
Solubility of multiple solutes and limits of solubility during freezing
I'm interested in modeling the freezing of solutions of water and I'm not really sure what happens in water after the solubility of a given material is reached. I know that as ice crystals form they ...
- 217
1
vote
0
answers
52
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How to calculate pH resulting from dissolving a salt in water? [closed]
The main question is how to calculate the changes in pH after dissolving a salt in water.
Suppose we dissolve 1 gram of magnesium carbonate (MgCO3) in 1 liter of Water. This will result in (...
- 11
6
votes
0
answers
164
views
Why is supersaturated sodium acetate so (meta)stable?
Sodium acetate is a common example used in general chemistry lectures to illustrate the idea of supersaturation, and that precipitation of a supersaturated solution can be initiated by a seed crystal. ...
- 161
1
vote
0
answers
57
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Can addition of a "neutral" salt like NaCl assist pH test strip measurement accuracy in low ionic strength/poorly buffered solutions?
After a web-search, it seems ISAs (Ionic Strength Adjusters) are offered commercially to assist pH electrode/probe measurements. Presumably meant to increase conductivity (without affecting pH ...
- 129
3
votes
1
answer
468
views
Is a diluted aqueous solution of sodium hypochlorite more stable than a concentrated solution, all else being equal?
On the Clorox website, they recommend that you dilute bleach (NaOCl) in water prior to use for disinfection. They say that you should make a fresh solution each time you need to use it, adding: “Don’t ...
- 159
-1
votes
1
answer
2k
views
Mixing hydrogen peroxide and sodium hydroxide doesn't lead to sodium peroxide anymore [closed]
I've been using same bottle of hydrogen peroxide and same bottle of 50 % of sodium hydroxide to make sodium peroxide for a month now. You could see the presence of sodium peroxide in the solution ...
-2
votes
1
answer
2k
views
Calculating molarity of iodine solution after reaction
I made an iodine solution referring to the methodology provided in this link:
https://www.thoughtco.com/vitamin-c-determination-by-iodine-titration-606322
$$\ce{KIO3 + 5KI + 3H2SO4->3I2 + 3H2O + ...
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3
votes
2
answers
1k
views
How do you achieve phase separation of a methanol / chloroform solution?
If I'm washing a methanol solution with chloroform, can I just add water in a 1:1 mixture with the methanol and expect it to break? Do I need to do anything else to cause the aqueous phase to separate ...
- 149
13
votes
2
answers
746
views
Do azeotropic mixtures evaporate proportionally?
Do azeotropes evaporate, without boiling, in proportionate amounts, or does this property describe their behaviour only at boiling point?
Concretely, if 91% isopropyl alcohol/water (by volume, i.e. an ...
- 241
-5
votes
2
answers
736
views
will splitting a solution will keep the concentration values (and moles) the same? [closed]
I have this exercise from my H.W:
and I am asked: if we split the solution into 3 different containers equally -
how many moles will the solution have in each container?
will the Cl- concentration ...
- 93
1
vote
1
answer
735
views
Hydration vs Dissolution
While revising Thermodynamics and Thermochemistry from revision material published by Arihant publications I encountered the following mentioned statement.
During dissolution, the physical state of ...
- 177
0
votes
0
answers
66
views
Osmotic Pressure of Aqueous Solution
The osmotic pressure of an aqueous solution at $25$ Celsius is $92.0$ $kPa$. Calculate the boiling point
of the solution. (Assume that the density of the solution is $1.0$ $g/mL$, ignore the mass of ...
- 117
-2
votes
1
answer
1k
views
Is mixture of ammonium hydroxide and ammonium nitrate a buffer solution? [closed]
Is a mixture of $\ce{NH4OH}$ and $\ce{NH4NO3}$ a buffer solution?
I have seen some examples with $\ce{NH4OH}$ and $\ce{NH4Cl}$ but never $\ce{NH4NO3}$.
- 1
0
votes
0
answers
126
views
Why is the Ag+ concentration in a beaker fixed in the reaction between excess AgCl (s) and KI (aq) from the start? [duplicate]
This arises as a sub-question for the following question: Calculate the concentration of I- in a solution obtained by mixing 0.10 M KI with an excess of AgCl(s).
I tried to look at How does addition ...
2
votes
1
answer
3k
views
Universal symbols for molar mass, molarity, and molality
This is a really basic (perhaps trivial) question, but I just want to confirm:
What are the SI symbols for molar mass, molarity, and molality? For molality and molarity, there is a difference, but I’...
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5
votes
1
answer
500
views
How do I calculate the amount of preservatives one would need for a cleaning solution?
I plan on making a very simple cleaning solution to clean metal contacts on PCB boards. It cannot contain anything that is flammable or hazardous so I've come up with the solution below.
Distilled ...
- 151
0
votes
0
answers
138
views
Problem in the calculation of ionic strength of a solution
Recently I've been trying to answer the question 10-13 (c) of 9th edition of Fundamentals of Analytical Chemistry of Skoog et al. Comparing my answers with the student manual , I realized that my ...
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-1
votes
2
answers
1k
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Why does a proton react with water to form hydronium ion and why does that ion has an overall positive charge? [closed]
Take this is an example:
$$\ce{HCl(aq) -> H^+(aq) + Cl^-(aq)}$$
and
$$\ce{HCl(aq) + H2O -> H3O+ + Cl^-(aq)}$$
Clearly the proton latches on to the water molecule but why? Also, why does the ...
- 19
1
vote
1
answer
130
views
What is the mechanism of endothermic dissolution?
My real question is in fact "How can dissolution happen if it's endothermic?" However, there
have been many questions regarding this exact topic and the answers about Gibbs free energy
...
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0
votes
0
answers
109
views
Comparative Solubility of Double Salts
Is there a tendency that could be used to generally forecast how a double salt might dissolve in aqueous medium compared to the simple salts of its constituents?
Example:
There is metal A, metal B and ...
- 1,097
0
votes
1
answer
213
views
Effect of mixing acids on solubility
Please help me clarify the title if you come up with a better way to put it (you certainly will).
My question is the following:
If you make a mix of equal parts of various acids (Bicarbonate, ...
- 1,097
0
votes
1
answer
254
views
How does solutions of two liquids work? [closed]
When two liquids mix, and they are not hindered by a polarity mismatch (like oil and water), why don't they always form a homogenous mixture? Due to entropy, a liquid will disperse itself evenly. This ...
- 205
2
votes
0
answers
78
views
Colligative properties: why does the size of solute not matter?
Colligative properties are defined as the "properties of solutions that depend on the ratio of the number of solute particles to the number of solvent molecules in a solution, and not on the ...
- 31
-1
votes
1
answer
340
views
Hydrogen and Hydrogen ion
Is it correct that a hydrogen atom only has 1 electron and 1 proton since the atomic mass is 1?
Also, is the hydrogen ion composed of a single proton and no electrons?
In an ionization process we know ...
- 15
-2
votes
1
answer
774
views
Copper anode dissolves in electrolysis of copper sulfate solution [closed]
I did an experiment with copper sulfate where you place two copper rods in an aqueous solution of copper sulfate. You apply an electric current and copper metal builds up on the cathode. I noticed ...
- 113
0
votes
1
answer
312
views
Find volume of ammonia gas required to prepare a solution of given pH [closed]
Calculate the volume of gaseous ammonia $(K_\mathrm{b} = \pu{1.8E-5})$ to dissolve (at NTP) in $\pu{100 mL}$ of water in order to obtain a solution with $\mathrm{pH} = 11.0.$ Consider volume variation ...
0
votes
4
answers
572
views
How many grams of sodium phosphate must be added to precipitate as much of one ion as possible?
Problem text:
Solid sodium phosphate is slowly added to $\pu{200 mL}$ of a solution containing $\pu{0.002 mol}$ of aluminum chloride and $\pu{0.001 mol}$ of calcium chloride (assuming no volume ...
- 111
1
vote
1
answer
2k
views
Using solubility product to determine the mass of the precipitate of a reaction
I mix together $\pu{100 mL}$ of an aqueous $\ce{NaCl}$ solution at $\pu{0.5 M}$ and $\pu{100 mL}$ of an aqueous $\ce{AgNO3}$ solution at $\pu{0.3 M}$. Assuming that the solubility of $\ce{NaCl}$ in ...
- 11
2
votes
1
answer
972
views
Creating a 10 ppb Lead Nitrate Solution
I’m trying to make a 10 ppb Lead Nitrate solution as part of a concentration calibration step for a Beer Lambert’s Law experiment. I plan on performing a dilution in three steps. The calculations have ...
- 467
-1
votes
1
answer
910
views
Why do azeotropes boil at constant temperature? [closed]
As given in the Wikipedia page,
An azeotrope (/əˈziːəˌtroʊp/) or a constant boiling point mixture is a mixture of two or more liquids whose proportions cannot be altered or changed by simple ...
- 623
-1
votes
2
answers
1k
views
In a double displacement reaction, why don’t the two products reform after being dissolved in water? [duplicate]
Let’s say I have $\ce{AB (aq) + CD (aq) —> AD + CB}$. When AB and CD are dissolved in water, they get dissociated into their component ions. But why don’t they reform as AB and CD, if it is already ...
-1
votes
1
answer
119
views
Difference between homogeneous and heterogeneous mixture [closed]
When i mix two equal but large number of stones it is possible (though extremely unlikely) that stone a and stone b perfectly segregate themselves into two halves or that they are uniformly ...
- 51