For questions relating to compounds dissolved in water and resulting reactions.

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Freezing point depression

Three aqueous solutions are made, $\ce{FeCl2}$, $\ce{NaCl}$ and $\ce{Na2S}$ all of which have the same molarity. Which two solutions will have the same freezing point depression? a. $\ce{FeCl2}$ and ...
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1answer
35 views

Cooling of solution [on hold]

The tea with sugar added in the first problem begins to cool. You notice that the tea begins to get cloudy and a white powder begins to form on the bottom of the cup. What is happening and why does ...
0
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1answer
30 views

Does adding mass to a liquid (not water) increase the volume

The Question sounds stupid but i have a legit problem I mixed 1000 mL coconut water and 225 g of agar-agar to make a coconut water [CW] agar. It gave me more than 1000 ml. the medium went beyond the ...
3
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1answer
42 views

Does a weak buffer solution still maintain a mostly steady pH if the acid or base load it has to buffer is small?

I need to buffer the $\mathrm{pH}$ of a solution to $3.0$ using a citrate buffer. I found a recipe to make a buffer solution that would use $82\%$ of $0.1\,\mathrm M$ citric acid (monohydrate) and ...
3
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1answer
33 views

How does salt concentration affect corrosion rate of iron?

I have conducted an experiment where I test the affect of $\ce{NaCl}$ concentration on corrosion rate of iron. I did this in an environment were all of the iron was submerged in water and the water ...
1
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1answer
32 views

What's the difference between aqueous NaOH and dilute NaOH?

Dilute $\ce{NaOH}$ can be prepared by adding a suitable amount of concentrated $\ce{NaOH}$. What's the difference between "dilute $\ce{NaOH}$" and "aqueous $\ce{NaOH}$"?
2
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1answer
214 views

Would sodium salicylate dissolve in HCl?

I've been searching around the web and the consensus seems to be sodium salicylate dissolves poorly in HCl because it would form salicylic acid. However, I don't understand why forming salicylic acid ...
4
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1answer
52 views

Why does phosphoric acid mask the colour of Iron(III) complex in water?

In the redox titration of Iron(III) with Permangante or dichromate we use Phosphoric(V) acid to "mask" the color of Iron(III) because it interferes with the end point colour change. What's the ...
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2answers
62 views

Liquid that looks like smoke when bottled?

I am making a gift that will consist of a liquid in a sealed bottle. I want the liquid to have a magical appearance. Something like the appearance of smoke - varying opacity from almost clear to ...
1
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0answers
20 views

Why is the enthalpy of solution for NaCl 3.88 and not 4.1 kJ/mol?

Based on Hess' law, the molar enthalpy of solution is equal to the sum of the enthalpies of formation of products minus reactants. In the case of dissolving table salt ($\ce{NaCl}$) in water, those ...
1
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1answer
16 views

Can I use fluorescence microscopy with a solution of hydrogen peroxide?

I want to use microspheres which have been dyed with a fluorescent dye for fluorescence microscopy in a solution that has a 1-5% concentration of hydrogen peroxide. Is this possible or will the ...
0
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1answer
45 views

Dissolve Silver Oxide

I was looking at how to dissolve silver oxide (in a solvent). I know that monovalent silver oxide will not dissolve in water, but are there any solutions in which monovalent silver oxide will ...
1
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1answer
67 views

NaOH to stabilize aqueous NaCN

This patent notes in passing: It may be necessary to add $\ce{NaOH}$ to stabilize aqueous $\ce{NaCN}$. Anyone skilled in the art would know the amount of $\ce{NaOH}$ to add. Obviously I'm not ...
5
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1answer
60 views

Electrolysis of water for demonstration: ideal electrolyte for safety, stability, conductivity, and ease of maintenance

I'm developing a system for educational purposes where electrolysis of water takes place. The aim is to practically show how electrical energy can be converted to mechanical, by electrolyzing water, ...
0
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1answer
24 views

What is the proper way to prepare a solution from hydrate?

I am following a protocol that requires me to prepare $10~ \mathrm{mL}$ $\mathrm{1~M}~ \ce{Ca(NO3)2}$. However, there is only $\ce{Ca(NO3)2*4H2O}$ in the lab. Originally I thought that all I have to ...
5
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1answer
51 views

Does the salt in the ocean act as a binding agent on sand?

When I walk on the beach, there appears to be an upper layer of the sand that is 'crusty'. This appears to be the opposite of what you see in sand in a dessert setting, where the individual ...
0
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0answers
23 views

How is Gibbs-Donnan equation derived?

Could it be derived from fundamental relations of gibbsian thermodynamics and other relevant physics? Or is the equation solely representing an experimental fact that only approximates the more ...
0
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1answer
57 views

Why is water's IR spectra indistinguishable from the IR spectra of a solution of glucose in water?

Anhydrous glucose has an absorption spectra (glucose IR spectra) that is quite different from the spectra of water (Liq. water absorption spectra). However, when a solution of glucose is prepared in ...
1
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1answer
60 views

How can I make a fairly saturated copper (II) sulfate solution by heating?

I have an investigation to do for my chemistry class. I'm looking at copper complexes and using ammonia to create a precipitate in the copper (II) sulfate solution, then redissolving the precipitate ...
3
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2answers
80 views

Is Hydrolysis same as dissolution?

I have book that contains the following paragraph: Due to high dielectric constant, it (water) has a very strong hydrating tendency. It dissolves many ionic compounds. However, certain covalent ...
3
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0answers
16 views

Measuring the effect of increasing salinty on the concentration of Dissolved oxygen

I want to investigate the effect of increasing salinity on the concentration of dissolved oxygen, in a water sample being distilled water. Would that work? My concern is, that since its not a true ...
4
votes
1answer
65 views

Why does CO2 lowers the pH of water below 7?

Ok so I understand that having a pH below 7 is considered to be acidic and I also understand that part of the definition of an acid is that it gives off H+ when dissolved in water(even though not all ...
5
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2answers
140 views

What happens to the bleach after mopping?

At home, I clean the tiled floors by mopping with highly diluted bleach. After mopping, I let the floor dry. What happens to the acid in the bleach? Will it crystallize on the floor, stay there ...
0
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0answers
16 views

Any Source for Water Methanol Composition Data?

I am making a composition inferential for water methanol solution. According to literature this is a non-ideal binary solution. So, I need a to devise a relation between Kideal and Kreal for both ...
4
votes
2answers
76 views

How can bromine water be called a solution?

Bromine water is a reagent which is used to test for unsaturation in organic compound. It is $2.8~\%$ bromine in water according to Wikipedia. But how is it made? This link describes the procedure ...
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0answers
25 views

Solubility of carbon dioxide in 1M sodium hydroxide solution?

I know carbon dioxide is soluble and forms carbonic acid but exactly how is solubility measured? How soluble is carbon dioxide in a 1M solution of sodium hydroxide?
3
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1answer
22 views

Writing equilibrium expressions with aqueous species

If we have the reaction: $$\ce{A +BC_{(aq)} <=> D}$$ where $\ce{A}$ and $\ce{D}$ are generic compounds (neither is pure solid nor pure liquid) and $\ce{BC}$ is an ionic compound dissociated in ...
0
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1answer
36 views

Dissociation of silver chloride in a solution

When silver chloride is exposed to light it can dissociate to silver metal and atomic chlorine. It might be a silly question, but could the chlorine go back into the solution as chloride ions ? if so ...
2
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0answers
31 views

Why is silver chromate red?

Copper(II) ions are blue and chromate(VI) ions are yellow therefore copper(II) chromate(VI) would turn out to be green because it's a mixture of blue and yellow. In the same way, silver ions are ...
0
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0answers
22 views

Does low solubility mean to have a solution that has a solubility of less than 0.1 M?

However, something is confusing in this sentence. "Equal volumes of 0.2 M compound A and 0.2 M compound B are mixed." ppt is formed which means low solubility, but why it is it 0.2 M? The Molarity ...
8
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1answer
91 views

Why aren't the copper(II) ions in CuSO4 precipitated by hydroxide ions from water?

From my own experience and literature, I know that $\ce{CuSO4}$ is well soluble in water and dissociates into $\ce{Cu^2+}$ and $\ce{SO4^2-}$. $\ce{Cu(OH)2}$, however, is not: $K_\mathrm{sp} = 2 \cdot ...
0
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1answer
50 views

Precipitation with NaI

I dissolved $\ce{[Pt(NH3)4](NO3)2}$ in water then I added small amount of $\ce{NaI}$ ($1~\mathrm{M}$) to it. Precipitation occurred. I want to know what happened?
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1answer
73 views

What determines whether a double displacement reaction will occur?

In normal displacement reactions, reactivity plays a large role and sometimes the reaction doesn't even happen. So is there anything limiting double displacement reactions? For example $\ce{2KI + ...
4
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1answer
48 views

Basic solubility problem involving precipitation

How do I found out how much $\ce{AgNO3}$ can be dissolved in 1 liter of solvent without precipitation of $\ce{AgCl}$. Solvent has $$M_{\ce{\,Cl-}} = 0.1\,{\rm M}\\M_{\ce{\,NH3}} = {\rm 1.00\,M}$$ ...
4
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1answer
38 views

Strontium Flame Test question

We did a basic flame test, and I understand that different salts produce different spectra because of atoms present in the salts. However, when I was doing the test, I noticed that when I dipped the ...
3
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0answers
54 views

Do filter-specific dyes exist? Equivalently, do dye-specific filters exist?

Apologies if this isn't chemistry enough for chemistry.se. I'm happy to go elsewhere if there are suggestions. Blue + Red = Purple is arbitrary here. If any different colors might make this more ...
0
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0answers
28 views

Separate Dextrose & Caffeine in water?

Can a dextrose / caffeine powder be (mostly) separated by dissolving in water then filtering the water? Dextrose is readily soluble in water (1-10 parts solvent to 1 part solute). Caffeine anhydrous ...
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0answers
25 views

I have two questions regarding equilibrium reaction [closed]

**First question: Here is my approach: ...
3
votes
1answer
43 views

How to minimise solution concentration changes due to evaporation?

Lets say I have a precise solution, and would like to store it long term (up to two years) with as little as possible change in concentration. The volume is 10-100ml. What container should I choose? ...
3
votes
1answer
42 views

Predicting pH of an acidic salt of an weak acid and weak base

Suppose we want to calculate pH of an $\ce{NH4HCO3}$ solution of known concentration. Now, $\ce{NH4+}$ will be hydrolised to give $\ce{H+}$ ions. Some $\ce{HCO3-}$ ions will be converted to (i) ...
2
votes
2answers
59 views

Common Ion Effect Calculations

Given a solution with a $\ce{S^{2-}}$ (sulfide ion) concentration of $2.76 \times 10^{-15}$ mol per litre, and $K_s(\ce{FeS})=4.90 \times 10^{-18}$, calculate the solubility of $\ce{FeS}$ in this ...
0
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0answers
7 views

How to increase saturation concentration? [duplicate]

Assuming pressure/temperature can't be changed, how would you increase the saturation concentration of Potassium Bicarbonate in water? Is it the same as increasing Ks? I heard about the different ion ...
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1answer
64 views

Acidic and alkaline salt solutions: why do some salt form acid/bases while others don't

I have a question regarding salts and their solutions. How come some salts, like sodium carbonate and ammonium chloride, produce acids/bases when dissolved in water? Moreover, how can you predict ...
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0answers
23 views

Different ion effect

I need to have the highest concentration of (bi)carbonate ions in a water solution. Thus far, my only idea was to use Potassium Bicarbonate (safe and cheap) as it has the highest solubility but it ...
4
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1answer
46 views

Does carbonated water change over the course of several days, or was my container leaky?

I have a Klean Kanteen flip-top growler, allegedly leakproof at up to 35psi of pressure, that I filled with some freshly-carbonated water 4 days ago — just to see how long it would last. I used a Soda ...
2
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0answers
45 views

Difference in color between the chromate and permanganate ions

As the title states, I'm wondering why the $\ce{[CrO4]^2-}$ and $\ce{[MnO4]-}$ ions display different colors in solution. Both of the metal ions have a $\mathrm{d}^0$ electron configuration, have the ...
2
votes
2answers
104 views

Does H2CO3 exist in solution?

When $\ce{CO2}$ reacts with water, it supposedly forms $\ce{H2CO3}$, which is the aqueous form of $\ce{CO2}$. But it is hard to isolate, but its $K_\mathrm{a}$ value is pretty low (on the order of ...
1
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1answer
23 views

Concentration of dissolved lead(II) bromide

Calculate the concentration of $\ce{Pb^2+}$ and $\ce{Br-}$ when $\ce{PbBr2}$ dissolves in water. $K = 7.9 \times 10^{-5}$ $$\ce{PbBr2 <=> Pb^2+ + 2Br-}$$ In most cases we have the ...
3
votes
2answers
48 views

Adding powdered Pb and Fe to a solution

My book states that if we add powdered $\ce{Pb}$ (lead) and $\ce{Fe}$ (iron) to a solution containing $1\ \mathrm{M}$ each of $\ce{Pb^2+}$ and $\ce{Fe^2+}$ it would result in formation of more ...
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0answers
20 views

Can a brine water electrolysis be looped?

Electrolysis of brine yields hydrogen and chlorine gases and aqueous $\ce{NaOH}$. So is it possible to combine the gases to form $\ce{HCl}$ gas, and mix it back with the aqueous $\ce{NaOH}$, so it ...