Questions tagged [solutions]
This tag should be applied to questions dealing with solutions of any kind. A solution is a liquid or solid phase containing more than one substance where, for convenience, one (or more) substance(s) called the solvent is treated differently from the other substances, which are called solutes. If water is the solvent, then the more appropriate 'aqueous-solution' tag should (also) be specified.
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Is it possible to make acids and bases in amphiprotic solvents other than water
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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Iodine solution concentration
I am planning to make 1L of 0.005M iodine solution from KI and I2. I have found instructions that say to use 2 g of KI and 1.3 g of I2 but no explanation why exactly this particular amount. I also ...
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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 ...
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Why Green Solution After Putting Bismuth Antimony in Nitrogen Acid
I am in a physics lab studying dislocation, and we submerged a bismuth antimony sample in nitrogen acid (about 50% concentration, if I remembered it right) as the first step to etch it. There were ...
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How to figure out concentration of ingredients in solution? [closed]
I have a solution that contains 3 inactive ingredients: ethanol, propylene glycol, purified water and 5% of an active ingredient.
What would be the smartest way to figure out the concentrations of the ...
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What solvents can I use to dissolve Epichlorohydrin rubber and Chloroprene Rubber
I am working with Epichlorohydrin and Chloroprene Rubbers and I would like to cast films of 2 mm at most. The solvents I have in my lab are DMSO, THF, DMF, Acetone, Ethanol and Propylene Carbonate. ...
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Vapour pressure and Raoults law [duplicate]
Suppose we take a binary ideal solution having components A and B .... let's say that their mole fraction is 1/3 and 2/3 respectively (for simplicity)
Now ... We know that this solution will start ...
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Why does ethanol decrease viscosity of a high pH carbomer solution more compared to water
Carbomer 407 is made up of acrylic acid that undergoes polymerisation to form a long linear structure. At higher pH, the carboxylic acid functional groups will dissociate to form carboxylate ions. ...
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Mixing two solutions: how to solve such problems, is there a trick? [closed]
Two containers were filled with salt solutions, and the first container contained 1 liter less solution than the second. The mass concentration of salt from the solution in the first container was 10%,...
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When does osmosis stop?
In the figure given below:-
Since only solvent particles can move through semipermeable membrane, if we manage to keep pressure on both the containers equal say by keeping weights, will osmosis go ...
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Anti-bumping granules
Anti-bumping granules are usually small stones. I presume that the principle of these granules ensuring smooth boiling, is that it blocks the upward motion of solution molecules.
Usually the stones ...
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Why don't P graphs contradict Raoult's law graphs?
Our teacher gave us the following question:
1 mole each of liquids A, B are mixed in a piston-type vessel and piston is moved slowly and isothermally. (PA0 = 75 torr and PB0 = 25 Torr)
Find:
(a) ...
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Does dissolution and crystallization always occur together?
Does dissolution and crystallization always take place simultaneously?
Also does crystallization also occur in unsaturated solution but its rate is less than rate of dissolution or is rate of ...
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Concentration term PPM [duplicate]
What volume do we assume when the concentration is written as mass by volume ppm?
I mean when mass by volume percentage is say 20%, we can say that 20g solute is present in 100 ml solution.
So if it ...
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Explanation for Raoults Law
The vapour pressure of pure liquids is independent of quantity of substance.
But when in a solution, the vapour pressure of the components are given by
$$P_A=P^°_AX_A$$$$P_B=P^°_BX_B$$
Since $A-A$, $A-...
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Why is glass a mixture and not a solution?
While studying mixtures and solutions, I read that glass is a mixture and not a solution.
Then I searched over the Internet about it, but I got the same answer that it is a homogenous mixture.
But ...
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Magnetic surface removal
I have a DIY project made from used hard disk. Certain HDD models contain precision glass disks plated with magnetic surface, usually done with magnetron sputtering. I am searching for a substance I ...
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Enthalpy change of a solution of 1-pentanol in 1-butanol
I came across a question asking to indicate the enthalpy of solution for a solution of 1-pentanol in 1-butanol.
The options were the following:
$\Delta H < 0$
$\Delta H \approx 0$
$\Delta H >...
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Why is it that in a buffer solution the equilibrium concentrations may be assumed to be the initial concentrations? [duplicate]
Considering the Henderson–Hasselbalch equation,
$$\text{pH} = \text{p}K_a + \lg \frac{[\ce{AcO⁻}]} {[\ce{AcOH}]}$$
$$\text{p}K_a = \lg \frac{[\ce{AcO⁻}][\ce{H⁺}]} {[\ce{AcOH}]}$$
Why are the values ...
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Why does the melting point of hexafluorosilicic acid differ that much in these two solution concentrations?
From the Wikipedia article for hexafluorosilicic acid:
Melting point:
ca. 19 °C (66 °F; 292 K) (60–70% solution)
$<$ −30 °C (−22 °F; 243 K) (35% solution)
What's the reason for this huge ...
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Why do laundry detergents go bad?
Common lore on the internet is that liquid laundry detergents go bad 1-2 years after they are purchased. Is this true? I'd like to understand the chemistry behind this. This is the laundry detergent I ...
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1
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How can a volatile solvent make an ideal solution with a non-volatile solid solute?
I ask because to make an ideal solution the intermolecular forces between the molecules of solvent and solute respectively should be similar and after mixing they should also be similar to what they ...
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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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How to prepare solution of liquid reagent of the given molar concentration?
I have a liquid reagent with molecular mass $M = \pu{294.08 g mol^-1}.$ I'd like to prepare $V = \pu{400 ml}$ of solution of that reagent with a concentration $c = \pu{100 mM}.$
Does it mean I have to ...
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Can acids contain OH-? [closed]
Given that a solution contains $\ce{OH-}$ ions can we sufficiently determine the substance is a base? From my understanding, an acid may still contain $\ce{OH-}$ ions. However, the concentration of $\...
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0
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How do I plot ternary phase diagrams using Flory-Huggins solution theory?
I have three components, $A,B,C$, with 3 exchange parameters: $\chi _{AB}, \chi _{BC}, \chi _{AC}$. I want to create a FH ternary diagram to see how such a mixture behaves and how phase separation ...
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Powder left everywhere after solution was left to evaporate. What could it be?
I dissolved a coin made of silver and copper and probably other metals in nitric acid. I neutralized the solution with some sodium hydroxide and then added salt(NaCl) to make Silver Chloride. A white ...
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Why do we have to prevent the hydrolysis of iron(III) nitrate?
I want to make particular concentration of ferric ions from $\ce{Fe(NO3)3.9H2O}$, and then I found this video
It says that we have to add nitric acid to prevent iron from hydrolysis, what does it mean?...
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Why causes the curvature of the line in pressure-composition graph?
I have been studying about liquid solutions and came across these graphs.
From the first graph it is evident that the solution considered has been assumed ideal as there is no deviation from ideal ...
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1
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What is the significance of semipermeable membrane in osmosis? [closed]
My teacher said that semipermeable membrane allows passage of only selected particles and then said that it is required for osmosis but I cannot totally understand the main function of semipermeable ...
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What is the relationship between solutions and changes to states of matter?
For example, when liquid water evaporates, my instinct is to say that of course it's become gas, but I'm a bit unsure because, if I understand correctly, evaporation occurs because air dissolves the ...
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Can you infer toxicity of an ionic compound based on the toxicity of its ions in other configurations?
Suppose I have two ionic compounds: "NaY" and "XCl". If these were both 'safe' to eat, would it be true that ...
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Watercolor pigment conundrum - can a change in ionic profile induce flocculation?
A client of mine has installed an ion exchange water purifier to de-harden her tap water. After that, however, she noticed that it has negatively affected her watercolor painting. From what she ...
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Why is solubility affected by temperature? [closed]
Why when we raise temperature generally a bigger concentration of a soluble gets dissolved in a inorganic solvent?Is there a quantum mechanical reason why this is happening?
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DIY Turbidity Standards?
I am trying to help my high school chemistry class make their own turbidity standards to calibrate the arduino turbidimeters they are making. Last year we tried calcium carbonate as it makes a cloudy ...
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What is the goopy substance that forms before CaCO3 precipitates?
I do a lab where we mix a solution of sodium carbonate with a solution of calcium nitrate. As expected, calcium carbonate (white solid) precipitates out. However, if the concentration is high enough, ...
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Does decreasing pH decrease solubility of adipic acid?
I added 3 grams of adipic acid to 150ml deionized water with heating + mixing until it was completely dissolved. This was then boiled and cooled to allow crystals to form. The maximum amount of adipic ...
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Any way to predict what quantities of heptane and chloroform will match the density of water?
I am trying to make a solution of heptane and chloroform that matches the density of water.
Is this something which must be done experimentally as it is generally unpredictable? Does a software exist ...
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Eutectic plot - freezing point lowering
I have a doubt about the correlation between eutectic plots and freezing point lowering.
The freezing point lowering, as well as all colligative properties, is defined in the presence of a volatile ...
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What are the reactions between Zinc acetate dihydrate and Methoxyethanol? [closed]
I am synthesizing a sol-gel solution with Zinc acetate dihydrate + Methoxyethanol and ethanolamine as stabilizer, and I wonder what are the reactions that are taking place in the process. Could you ...
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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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How come in biuret test the copper sulfate doesn't react with the sodium hydroxide?
As I understand the color change in the biuret test is due to the formation of a complex between the peptide (with more than 2 peptide bonds) and the $\ce{Cu^2+}$ ion, from $\ce{CuSO4}$. But before ...
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Decarboxylation of THCA in cannabis after plant material is mixed with ethanol [closed]
When making a tincture of cannabis, an early step is decarboxylation by roasting cannabis flowers at low temperatures (such as 230F for 30 minutes). My question is, how can one decarboxylate cannabis ...
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Electrolysis of Solutions
So far I've only encountered formulas to solve for solutions of single molecules while learning about electrolysis, i.e. H2O or FeCl3. This generally has involved determining the resultants, ...
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Colligative properties and binary phase diagrams
I'm having troubles with colligative properties and how to relate them to binary liquid-vapour and solid-liquid phase diagrams.
First of all, in my book it is indicated that colligative properties are ...
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1
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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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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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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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Why is water present in "pure" nitric acid and RFNA and WFNA?
Various types of nitric acid have been used in rocket fuels as oxidisers (RFNA is red fuming nitric acid, WFNA is white fuming nitric acid) as they are often hypergolic with a wide variety of fuels.
...
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Silver recovery from sodium hydroxide solution
I have washed graphic film with sodium hydroxide solution removing the silver emulsion. Is there any way to now recover the silver from solution?
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