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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What is the difference between reacting and dissolving?
When one chemical is added to another how would we come to know whether the compound dissolves in it or reacts with it? For example $\ce{AgNO3}$ dissolves in $\ce{CCl4}$ whereas it could also have ...
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To mix sodium borohydride and boric acid [closed]
What concentration of 50ml boric acid should I make to mix with 50ml sodium borohydride, so that the total concentration is 1mM? What should be the individual concentrations of the solutions to make a ...
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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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Why zinc sulphate solubility is higher in ethylene glycol than water?
I'm trying to find saturation point for dissolved zinc sulphate in water and ethylene glycol.
Based on my knowledge, water is more polar than ethylene glycol as reflected in its higher dielectric ...
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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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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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Entropy as the driving force for osmosis
How is entropy responsible for osmosis and is movement of solvent possible from its higher concentration to lower concentration?
By concentration, I will be referring to the concentration of solvent ...
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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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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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Are hydroxides soluble in each other?
Let's say I have molten potassium hydroxide and then I add some Calcium hydroxide. I imagine, since there are hydroxide groups floating around, it would be energetically neutral for the calcium ions ...
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Balancing a chemical reaction with oxidation numbers
We have been teached how to balance chemical reactions with oxidation numbers in school, but somehow I can't understand it.
This is the equation to balance
$$\ce{Cu(s) + NO3−(aq) + H+(aq) -> Cu^2+(...
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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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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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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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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 concentration of solutions of alkali metals in liquid ammonia change the magnetic properties?
In "NCERT Chemistry for Class XI - Volume II", in chapter "s-block elements", under the topic "Chemical Properties of alkali metals", it is given:
(vi) Solutions in ...
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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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Calcium-containing acidic solution
I want to prepare an acidic solution containing Ca ions. I thought about dissolving calcium sulphate, acetate or phosphate in $\pu{2 M}$ $\ce{H2SO4}$ or $\ce{H3PO4}$ solutions, but it seems that $\ce{...
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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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Confusion on when to use mass of entire solution when performing q=mc∆T
I am studying for the AP Chemistry exam in May 2020. While studying, I encountered a doubt.
In Problem 1 (the question on the top), the educator saw that the problem was referring to the solution as 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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Thickening and/or slowing evaporation of IPA-based ink
The conundrum
I have a security printing ink that I make by adding an IR-absorbing dye to a 50/50 mix of Isopropyl Alcohol and distilled water. The ink solution is pale green but dries virtually ...
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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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Advice on forming a 10% solution of Maltol
I’m having great trouble forming a 10% solution of Maltol. Specifically, I’m trying to dissolve 3 grams of Maltol in 27 grams of solvent.
I’ve tried everything from Propylene Glycol, to Deionized ...
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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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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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How soluble is uranium in molten iron?
As I know, uranium and iron simply aren't mixable, which means there are no U-Fe alloys. The Google says, uranium is insoluble in molten iron.
But, if something is "insoluble", it actually means only ...
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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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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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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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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 does the osmotic pressure method offer an advantage over other methods of molar mass calculation? [closed]
Measurement of osmotic pressure provides another method of
determining molar masses of solutes. This method is widely used to
determine molar masses of proteins, polymers and other macromolecules. The ...
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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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When is Raoult's Law valid for solid-liquid solution?
Raoult's Law for solid-liquid solution is stated as such in my books that it is applicable for all non-volatile solutes.
However different solutes must have different attractive or repulsive forces ...
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What is the maximum osmotic pressure that can be exerted with water as the solvent at room temperature?
Lets say we have a membrane which separates a tank of pure water from a tank of water saturated with a solute(there are also undissolved chunks of solute which can immediately dissolve if water is ...
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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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How to filter out magnesium acetate (a soluble salt) quickly and cheaply from water
I am conducting an experiment that involves reacting a weak acid and a weak base to form water and a salt with this overall equation
$$\ce{Mg(OH)2(s) + 2CH3COOH(l) <=> 2H2O(l) + Mg(CH3COO)2(aq)}...
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What is the derivation for the expression of depression in freezing point?
In my textbook, it is written that the expression for depression in freezing point is
$$\Delta T_\mathrm f=K_\mathrm f\cdot m$$
where $\Delta T_\mathrm f$ is the freezing point depression (defined as ...
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