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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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280 views

Is the crystallization process of aqueous solutions of substances such as lithium chloride endothermic?

$\ce{LiCl}$ has an enthalpy of solution of $\pu{-37.1 kJ/mol}$, so its dissolution process is exothermic. Does this mean that it's crystallization process is exothermic? I'm asking since I've looked ...
3
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2answers
3k views

Is sodium acetate strong or a weak electrolyte?

Since it is formed of a strong base and a weak acid it should be a strong electrolyte but a chemistry teacher said that it is a weak electrolyte.....
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0answers
1k views

Why do chloroform and benzene exhibit negative deviation from Raoult's law?

Chloroform is a polar molecule, and benzene is nonpolar. Shouldn't the chloroform-chloroform and benzene-benzene intermolecular forces be stronger than chloroform-benzene interactions (like dissolves ...
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0answers
205 views

Gibbs energy of dissolution

I would like to calculate the gibbs energy of dissolving NaCl in water, NaCl(s) -> Na+(aq) + Cl-(aq) I am using the equation, G=RTln(K) Where K=[Na+][Cl-] What I find confusing is that Gibbs ...
3
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0answers
104 views

What determines the maximum size of salt crystals as grown in flux growth?

Like many other children, I grew single crystal salt crystals in a salt solution. This is a common and fun experiment for children. However, with both this experiment, and with flux growth methods ...
7
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1answer
127 views

Is it possible to have Volume(solution) < Volume(solvent before adding solute)?

I understand the answer to the question "Is it possible to have Volume(solution) < Volume(solvent) + Volume(solute)?" is "yes" -- but it is possible that adding a solute causes the solvent to ...
3
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0answers
47 views

Why does soapy dishwater lose soapiness over time?

I wash dishes by making a concentrated solution of dishsoap (eg dawn) and water. Sometimes I'm lazy and forget to wash the container containing the soap solution, and it sits on the counter overnight....
11
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2answers
5k views

Why does like dissolve like?

Polar solvents love polar solutes to be dissolved in it and non polar with non polar. Often said as like dissolves like. Okay, polar loving polar can be understood with help of the facts: same polar ...
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0answers
17 views

Do ionic substances dissociate in gaseous solvent [duplicate]

Mostly when we think of dissociations of compounds we think Compound + Water(l) → constituent ions Normally this takes place in test tubes and beakers and human hands (warning: may be painful) and ...
2
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1answer
46 views

Binary diagram and two phase region

I know that to find the composition in a two phase region of a binary diagram we have to draw the isotherm and to look at the intersection with phase boundaries. But why? Is there a demonstration?
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1answer
212 views

what is the final concentration of the mixture [closed]

In a bizarre twist of chemical fate, an accident results in you results in you mixing 2L of a 3.00M solution of NaCl with 4L of a 1.50M solution of NaCl. what is the final concentration of the mixture?...
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1answer
229 views

How do Invert Sugars deter crystallization in Sucrose solutions?

Invert Sugars, by themselves, are notorious for their reputation to crystallize fast (think honey), but their addition to solutions of Sucrose (think simple syrup) deters the crystallization process. ...
2
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0answers
149 views

Heat and Sugar Syrup Consistency

I make my own sugar syrups and have been observing how heating the syrup to different degrees results in syrups of radically different consistencies, I wonder why. Heating up syrups (4:3 Sugar:Water) ...
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0answers
35 views

How can it be determined that a liquid is saturated with a gas?

How can it be determined if a liquid is saturated with a gas? For example, if I am introducing carbon dioxide to water at 40 PSI at 35F in a sealed container, how would I know at what point the water ...
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0answers
22 views

Determining pH of immunoprecipitation buffer recipe

I'm following a protocol for extraction of proteins from yeast, and I came across this recipe for immunoprecipitation buffer: $\pu{50 mM}$ HEPES-$\ce{KOH}$, pH 6.8, $\pu{150 mM}$ $\ce{KOAc}$, $\pu{...
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1answer
84 views

Symantics of parts per (million, billion, etc)

I have always thought that parts per million meant that in a solution of one million particles, one of those particles is the particle that you are looking for its concentration in ppm. However ...
5
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1answer
78 views

In the nonideal solution, why can't one of the solute be positive deviation and the other be negative deviation?

In the nonideal solution, why can't one of the solute be positive deviation and the other be negative deviation? Let's say A and B makes a nonideal solution. The moleculat force between A and B means ...
2
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0answers
247 views

What solution is not in equilibrium?

An example of a solution not in equilibrium (A) Chemical ph indicator (B) Acid/base buffer (C) Anhydrous solution (D) hypotonic solution (E) Supersaturated solution I eliminated A and ...
2
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2answers
2k views

Why doesn't a buffer solution change ph(Appreciably?)

Consider a buffer solution containing weak acid $\ce{CH3COOH}$ and its salt $\ce{CH3COONa}$: \begin{align} \ce{CH3COOH &<=> CH3COO- + H+} \tag{1}\\ \ce{CH3COONa &-> CH3COO- + Na+} \...
3
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1answer
167 views

How to determine fire hazard of heating ethylene glycol to dissolve borax and boric acid

I am looking to replicate instructions provided in the last paragrph of this article that requires dissolving borax (Sodium Tetraborate decahydrate ($\ce{Na2B4O7·10H2O}$)) and boric acid in ethylene ...
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0answers
51 views

SO3(2-) to Na2S2O5 ratio

Is there a way of calculating the amount of sodium metabisulfite from the sulfite content? I found online instructions for the test kit for sulfite that suggests multiplying by $2.37$ to obtain $\pu{...
0
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0answers
144 views

when preparing a supersaturated solution, does the crystalization occur immediately?

I have gotten slightly confused on how the crystallization process exactly occurs when preparing a supersaturated solution. Say we prepare a supersaturated solution by the usual process, first ...
22
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1answer
566 views

How to think of solvated electrons?

This excellent answer explains at length what's happening in this fascinating video entitled Liquid Electrons - Periodic Table of Videos. In the screenshot below, the metallic-looking solvated ...
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0answers
82 views

How to interpret the shape in this representation of an electride?

This excellent answer describes the appearance of solvated electrons in ammonia as first a blue, and then metallic color. It is produced by dissolving sodium in ammonia at low temperature. According ...
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1answer
43 views

Peroxide without hydrogen [closed]

How come we always see hydrogen peroxide and never peroxide by itself. Is there such a thing as peroxide ? Does this exist in nature? Why is hydrogen always associated with it? Please note: First ...
8
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2answers
638 views

How can we tell the particle size of solutes in solutions?

This is a general question in regard to solutes dissolving into solvents. I am interested in the reality of the particle size of the solute during dissolution. For example, take $\ce{NaCl}$ and ...
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1answer
72 views

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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1answer
6k views

Solubility of Aluminium Hydroxide in Sodium Hydroxide Solution

Aluminium hydroxide is not soluble in water at all, however I was doing some reading and read that it does in fact dissolve in a solution of sodium hydroxide. This just seemed a bit strange to me, so ...
1
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1answer
17k views

What is the relation between molarity and molality? [closed]

Is the following equation correct: $$m = \frac{1000 \times M}{M \times M_b - 1000 \times d},$$ where $M$ - molarity, $m$ - molality, $d$ -density of solution, $M_b$ - molar mass of solute?
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1answer
306 views

How can I calculate the molar conductivity of a solution with multiple solutes?

I'm running an experiment mixing 2 different solutions, $\pu{5 mL}$ of $\pu{0.1 M}$ $\ce{NaCl}$ with $\pu{5 mL}$ of $\pu{0.1 M}$ $\ce{KCl}$. I am measuring the conductivity of the total solution in $\...
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1answer
489 views

Does Ksp depend on the solvent?

E.g. would the solubility and Ksp of $\ce{Mg(OH)2}$ be the same in water as it would be in HCl? Doesn't solubility depend on the polarity of the solute and solvent, so wouldn't different amounts of a ...
4
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1answer
150 views

Why does the conductivity of a LiOH solution decrease when boric acid is added?

If I start with pure water and add $\ce{LiOH}$ the conductivity of solution increases. However, if I then dissolve boric acid in the same solution the conductivity falls. I would have thought adding ...
4
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1answer
4k views

Reaction of iron(III) oxide with nitric acid [closed]

I'm currently working in a project in which I have to convert the iron oxides present in iron ore slime into ferric nitrate. Iron ore slime is which has the particle size of below $\pu{0.15 mm}$ is ...
2
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1answer
393 views

Solution to Raoult's Law for a volatile binary solution (no pun intended)

Raoult's Law In a closed container, $$P_A=P_A^\circ x_A$$ where $P_A$ is the pressure of compound in gaseous phase, and $x_A$ is the mole fraction of the liquid component A in the liquid mixture. If ...
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0answers
357 views

Predicting the vapor pressure of water ammonia solution

I am working on a project that involves the compressors for a vapor compression refrigeration cycle of R717 (ammonia) and came across something that has been boggling my mind a little bit for no good ...
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2answers
3k views

Calculating concentration of H+ Ions using Ka Value [closed]

I have this homework question that I am a bit stuck on for an answer. If anyone could help that would be great. Question: For a $\pu{0.2M}$ $\ce{HNO2}$ solution ($\pu{K_a= 4.5 \times 10^{-4}}$) ...
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2answers
3k views

Why would a solution of FeCl2 appear brown/yellow sort of like FeCl3?

If we prepare a solution of $\ce{FeCl2}$ by dissolving solid $\ce{FeCl2}$ powder in water, supposing the bottle of $\ce{FeCl2}$ was left open for sufficient time, is it possible for $\ce{FeCl2}$ to ...
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1answer
513 views

Will water allow salts to be dissolved in methanol (that are otherwise poorly soluble)?

If we make a mixture of water, methanol and a salt like $\ce{FeCl2}$, $\ce{NaCl}$ etc, will the ability of water and methanol to mix allow $\ce{FeCl2}$ and $\ce{NaCl}$ to be a part of this mixture and ...
10
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2answers
1k views

Can I pour a solution into another vessel with no air bubbles?

I have been trying to create a method to create a homogeneous agar solution. What are appropriate techniques to ensure homogeneous solidification of an agar-based aqueous solution? The new solution ...
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1answer
732 views

Baking soda + oil solubility

I have a question regarding the solubility of baking soda (bicarb soda) in oil. I am pretty sure that it has poor solubility, but I have a chemistry dilemma and cannot seem to solve it. I make all-...
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0answers
108 views

Adding fragrance oil to paraffin wax

I am trying to make a highly scented jar candle. I'm having trouble wicking the candle when I put in larger amounts of fragrance oil. It seems to be either too small and drowns or is too large and ...
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1answer
291 views

Acid-Base buffer question

Calculate the change in pH of a buffer made by combining $\pu{500 ml}$ of $\pu{0.1 M}$ $\ce{CH_3CH_2COOH}$ and $\pu{500 ml}$ of $\ce{CH_3CH_2COONa}$, when $0.04$ moles of $\ce{NaOH}$ is added to the ...
4
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2answers
210 views

Finding sulfate contamination in crystallized silver nitrate

What is the best way to check for a small amount of sulfate contamination (if any) in silver nitrate? Usually, I would use dilute barium chloride to precipitate out the resulting insoluble white ...
3
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1answer
42 views

How to add a color to vapors?

I want to add a color to vapors, like the vapor that comes out of glycerine when heated. Is there a chemical compound I can put into glycerine that makes the vapor colorful? Or is there a chemical ...
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0answers
217 views

Methods to extract sucrose from tea after it's been stirred in?

Sugar is often labelled "white poison" now-a-days and a lot of negative health consequences happen due to increased sugar consumption. Keeping this in mind, if I were handed a cup of tea (with sugar ...
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1answer
865 views

How can I convert weight percentage of calcium chloride hexahydrate to calcium chloride dihydrate? [closed]

I have a chemical formula with $27\%$ $\ce{CaCl2.6H2O}$ and $43\%$ water with the balance of $30\%$ being other chemicals. I want to convert the $\ce{CaCl2.6H2O}$ and water percentage to $\ce{CaCl2....
21
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1answer
921 views

Is it possible for a compound to be soluble in a mixture of solvents but not the individual solvents?

Some weeks ago one of my friend needed to use turpentine. As a good but ignorant chemist on that point I did some research about it. I found (at the beginning) in the French wikipedia page of ...
5
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1answer
125 views

What are appropriate techniques to ensure homogeneous solidification of an agar-based aqueous solution?

I am making a T1 weighted phantom for an MRI project. I'm trying to see if I can calculate how much a persons head heats up during an MRI scan. It consists of distilled boiling water, $\pu{7 g/L}$ ...
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0answers
233 views

How do you neutralize pH of a solution by not knowing concentration [closed]

If I had a pH 10 in a 100ml solution of water and 93% sodium hydroxide how much mg/l of 93% sulfuric acid would we need to use to reach a pH of 4. From my dated college chem books and a lot of google ...
6
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1answer
130 views

How do phase transfer catalysts bring anions to organic phase?

Many anions are quite stable in the aqueous phase, but not so much in organic solvents where its necessary to perform some reaction (usually nucleophilic substitutions). I have heard that crown ethers ...