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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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Unit conversion of Molar Conductivity

I know this might be a silly question but I am confused with different answers of internet. My question is: Molar conductivity is given as: Molar conductivity = $k÷M$. SI unit of : k is S/m & ...
4
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2answers
80 views

If some particles of liquid in a solution convert to vapour then why can't some liquid particles convert to solid?

I was reading about the vaporisation of liquid when I came across the following statement. The average energy of the particles in a liquid is governed by the temperature. The higher the ...
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1answer
376 views

Extract ammonium sulfate from water

What is the best method to extract ammoniumsulfate from water? The assignment is as follows: Manure is being processed and the product left is a mixture between water and ammonium sulfate, ...
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1answer
869 views

How many grams of CuSO4*5H2O yield 10 grams of H2O?

If I want there to be 10.00 g of water in the copper (II) sulphate pentahydrate sample that I'm measuring, what mass of the substance will I need in order to have 10.00 g of water? I solved this ...
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1answer
2k views

Differences between miscible and soluble

What are the differences between soluble and miscible? So far I found this (page 3 http://faculty.sites.uci.edu/chem1l/files/2011/03/D01MANmiscibility.pdf): soluble=solid dissolves into a liquid ...
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1answer
73 views

Removing potassium chloride crystals from a mineral composed of manganese dioxides

How can I remove crystals of potassium chloride from a mineral composed of manganese dioxides? Hey, i'm a high school student trying to do a good cryptomelane sample to use in my scientific project. ...
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2answers
404 views

How to dissolve cat hair without effecting fabric?

I am wondering if it is possible to create some sort of a solution that will dissolve cat hair (or dog hair), but, is not harmful to the surrounding fabric? I am picturing a solution you would soak a ...
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1answer
791 views

Why is finding [H+] when given [OH-]= 3.57e-5 M wrong when I use -log[OH-]?

Question/Problem I know that [H+][OH-]=$10^{-14}$ And the problem asks to find out the concentration of H+ when the concentration of OH- is $3.57*10^{-5}$M By using the equation above i find that ...
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1answer
119 views

Negative ions affecting galvanic cell voltage

I don't see why negative ions don't affect the voltage. I mean the electric field of a negative ion like $\ce{SO4^{-2}}$ is not like what $\ce{NO3-}$ produces that means that it should affect the ...
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1answer
93 views

organic hard surf wax?

I made some organic surf wax with 4 parts beeswax and 1 part coconut oil. The wax turned out to be sticky but had no tack. I'd like to make wax for warm water that forms a layer of hard bumps on the ...
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2answers
198 views

how are colloids and suspensions solutions?

my definition of solution is a homogenous mixture of a solute and solvent. and in my textbook they call colloids and suspensions solutions . how is this possible if both of them are heterogenous ...
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4answers
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A drop of water in a tin of sugar: Which one's the solvent, the sugar or the water?

The other day, when we were dealing with the chapter Solutions, our teacher asked us this: If I add a drop of water, to a tin full of sugar (without mixing it in), what's the solvent here? The ...
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1answer
8k views

Why do non-polar covalent compounds dissolve in non-polar covalent compounds only?

My textbook says that electrovalent and polar covalent compounds dissolve in electrovalent compounds and polar covalent compounds but not in non-polar covalent compounds. I understand the reason for ...
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2answers
19k views

How to determine which aqueous solution has the largest freezing point depression

Question This is more of a conceptual question. Let's say that we are given different aqueous solutions and we are asked to choose the one with the highest freezing point depression, which do we ...
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0answers
35 views

Diffused Layer ion in Electrix Double Layer

When KI is added to AgNO3 soln, so AgNO3 is in excess, collidal particle is AgI:Ag+ with diffused layer of I-, Why is the diffused layer not of NO3- when the anion in excess is NO3-? If we had KI in ...
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1answer
413 views

Finding the molarity of an acid in a titration

I was doing a question that asks the molarity of a 10 mL of tartaric acid that is titrated to phenolphthalein endpoint with 20 mL of 1.0 M NaOH. I worked it out by equating the molarity of the NaOH ...
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1answer
2k views

Boiling point elevation for a mixture of ethanol and water

Properties such as boiling point, freezing point and vapour pressure of a pure solvent change when solute molecules are added to get homogeneous solution. These are called colligative properties....
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1answer
31 views

Confusion over percentage volume

We've been told our lab report has to be written with "% v/v" instead of volume. I understand how to calculate it, however I'm unsure if I'm doing the right thing when it comes to using it later on. ...
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1answer
159 views

Chemical in (s) mixed with chemical in (aq) vs. chemical in (aq) mixed with chemical in (aq)

Hopefully the title is comprehensive enough. But I am wondering, does it make a difference if you take a powder and mix it with an aqueous solution or take a solution with the very same chemical ...
4
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1answer
624 views

Finding out pKa of acid from molar conductivity

I'm reading about the electrical properties of solution where there is a problem like that: The molar conductivity of $0.0250\ \mathrm M$ $\ce{HCOOH(aq)}$ is $4.61\ \mathrm{mS\ m^2\ mol^{-1}}$. ...
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0answers
52 views

Is it possible to supercool hydrated salts like magnesium nitrate hexahydrate supercool just like for sodium acetate trihydrate?

Recently I stumbled upon the phenomenon of supercooling. I know that you can do this with water as well as with some phase change materials, like sodium acetate trihydrate (from the wintersport ...
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1answer
886 views

Molarity of an ion

What is the molarity of sulfate ions in a 0.010 M of aqueous aluminum sulfate solution? Can someone explain this question for me. I know the compound is $\ce{Al2(SO4)3}$. Does that mean I just ...
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1answer
147 views

Why is the strong acid written in a net ionic equation? [closed]

Strong acids dissolve and break apart into ions, so in a net ionic equation, why are they written?
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1answer
457 views

How to measure concentrations using emission spectrum?

Imagine I am using emission spectroscopy to identify the presence of ions in a solution. Would it be possible to use the intensity of the spectrum to find the concentration of each ion in the ...
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0answers
38 views

Ionic emission spectrum contamination

Imagine that I am trying to identify the presence of ions from among the metals $\ce {Li,Na,K,Ca,Sr, Ba}$ in some solution through their emission spectrum. By mistake the wire used to introduce ...
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1answer
63 views

Any differences in metal ion emission spectra?

If I measure the emission spectra of potassium using the following solutions 1) $0.1~\mathrm{M}$ of $\ce{KNO3}$ 2) $0.1~\mathrm{M}$ of $\ce{K2SO4}$ will I see any significant differences? I think ...
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0answers
789 views

Find the standard Gibbs' free energy of formation at 298.15 K for O2 gas dissolved in the saturated aqueous solution?

The solubility of $O_2(g)$ in water at $25^o \text{C}$ and $\text{1 bar}$ pressure of $O_2(g)$ above the solution is $0.00126$ $mol$ $O_2(g)/kg$ $water$. Find $\Delta_fG_{298.15}^o(O_2(g),sln)$. I ...
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2answers
191 views

How to make a CCl3F Fluorine NMR standard?

I am running some fluorine NMR and would like to make a bulk solution of $\ce{CCl3F}$ in $\ce{CDCl3}$ to aid in assessing the amount of fluorinated product present by having my NMR solvent act as a ...
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0answers
397 views

Calculating the pH of buffer solution made of two salts of a polyprotic acid

When we are making a buffer solution by solutions of a weak acid and its salt like $\ce{CH3COOH}$ and $\ce{CH3COONa}$, or by a weak base and its salt like $\ce{NH3}$ and $\ce{NH4Cl}$, we can use the ...
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1answer
408 views

Interpreting the phase diagram of a minimum boiling azeotrope

Exactly what does the line AB signify in the above phase diagram? Also, why is the curve divided at the azeotropic point?
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2answers
443 views

Solubility product of HgS

The reported solubility product of $\ce{HgS}$ is $4 \times 10^{-54}$. How is this possible? The minimum concentration that is possible is 1/avogadro's constant which shall be about $10^{-23}\ \mathrm{...
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0answers
51 views

Calculation of equilibrium constant of mixing

Hydrocyanic acid in benzene solution forms both single and double molecules; in aqueous solution only single molecules are present. A series of different aqueous solutions of HCN were shaken with ...
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2answers
2k views

What is the difference between a mixture and a solution?

Is there an actual difference, or are they synonymous?
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1answer
98 views

Is it possible to create a solution with superoxide?

I am not a chemist, and somehow I cannot find any material on this topic, so I decided to ask here. I am looking to create a solution with a specified amount/concentration of superoxide ($\ce{O2^.-}$)...
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1answer
470 views

Verification of variants of the Ebullioscopic formula

Wikipedia cites the following formula for the ebullioscopic constant $K_{\mathrm{b}}$ regarding the elevation in boiling point of a volatile solvent upon addition of a non volatile solute (https://en....
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1answer
213 views

Is blowing air (from lungs) into a water/soap solution changing the liquid into a gas contained in the bubbles?

I am teaching an art lesson to second graders. We are going to blow bubbles into a dyed soapy solution and then place the bubbles on paper. When the dyed bubbles pop, it makes for a great bubbly ...
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2answers
434 views

Interpretation of miscibility curves

I stumbled across miscibility curves in the section Solubility of Liquids in Liquids (Organic Chemistry, by Wallwork and Grant) today. I'm not sure if my problem is with the way the content was laid ...
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1answer
655 views

What if solute and solvent exist in equal quantities?

A solution is made of solute and solvent, like salt in water, however, what if the solute and solvent exist in equal quantities? Which one is the solute and which is the solvent? If one of them is ...
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0answers
359 views

What's the van 't Hoff factor of dilute aqueous ferrous sulphate solution?

Is it more than one or less than one? Here is what I think: since it is a dilute and aqueous solution, so $\ce{FeSO4}$ will be hydrated and new formula will be $\ce{FeSO4*7H2O}$. Thus, the ...
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0answers
49 views

Does the dissolution of sugar in an espresso lower its temperature?

The question originates from a few coffee breaks at work. My colleague is sure that an espresso with sugar has a lower temperature than an espresso without sugar. Is it true and, more importantly, ...
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1answer
466 views

Is it possible to detect and measure the amount of potassium sorbate used to preserve fruit juice?

In a store bought fresh orange juice that is preserved using potassium sorbate is it possible to detect the presence of potassium sorbate and also measure the amount present? What methods of testing ...
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1answer
1k views

How to calculate the pH of a propanoate buffer after addition of sodium hydroxide?

I've calculated the pH of the buffer solution, as seen. The question I'm referring to is part d), which asks: 'Calculate the pH of the solution after 0.01 mols of NaOH are added to 500$cm^3$ of the ...
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2answers
224 views

How does a glow stick work [duplicate]

I understand that when the glow sticks snaps, it produces light, and that process is called triboluminescence. But I don't understand how that works
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2answers
503 views

How to dissolve a spider with household chemicals?

Somehow a spider got into the little window that shows the water level on my electric kettle. The kettle doesn't come apart very easily, and it looks like I can't get this part off without breaking it....
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1answer
868 views

Suitable antifreeze solution

If glycerine $\ce{C3H5(OH)3}$and methyl alcohol $\ce{CH3OH}$ are sold at the same price per kilogram, which would be cheaper for producing an antifreeze solution for the radiator of an automobile ...
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0answers
619 views

Concentration of salt in the Dead Sea

How can dead sea have the salt concentration (w) of 29% when the mass fraction of a saturated NaCl + H2O is 26.5% (at 20 degrees celcius)? Thank you. EDIT: Dead Sea salt concentration is 34.2% and ...
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2answers
487 views

Is it true that calcium carbonate is more soluble in NaCl than deionized water?

I have two mixtures: $\ce{CaCO3}$ in NaCl and $\ce{CaCO3}$ in deionized water (DI). Is it possible to get more $\ce{Ca^2+}$ ions in NaCl solution than DI?
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1answer
2k views

Why is DMSO more polar than other solvents, yet it dissolves ionic compounds worse?

I'm working right now in the solvent importance in ionic character, and I noticed how a binary salt ($\ce{CuCl2}$) dissolved better in methanol than in dimethylsulfoxide, and in contrast, a ...
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1answer
1k views

How to calculate the mass of water to add to copper(II) sulfate to form a 4% solution?

How many grams of water are required to make a $4.00\%$ solution with $15.0~\mathrm{g}$ of copper(II) sulfate pentahydrate? I calculated the percent composition of water in a molecule of $\ce{CuSO4....
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1answer
2k views

How to get rid of bubbles?

Certain solutions, such as aqueous SDS or soapy waters, after being shaken evolve a lot of bubbles. These bubbles disappear over time, but it can take minutes or sometimes hours (eg. for 20% SDS). Is ...