Questions tagged [aqueous-solution]

For questions relating to compounds dissolved in water and resulting reactions and acid-base equilibria.

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4
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4answers
23k views

Difference between precipitation and crystallisation

What is the main difference between precipitation and crystallization. Is precipitation a chemical change and crystallization a physical change. How can we say that the resulting solute is precipitate ...
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4answers
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Causing a metal or glass marble to float in an aqueous solution

I am trying to find a way that you could cause metal (Aluminum) or glass to float in a mixture of water and some water-soluble material. I am aware that salt can be used to heighten the density of ...
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2answers
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Why do metals form ions in solution? [closed]

I'm looking at redox half-reactions, such as the one below: $$\ce{Zn(s) -> Zn^2+(aq) + 2 e-}$$ Does the zinc react with the water and dissociate into ions? Why doesn't solid zinc have a charge?
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2answers
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Caffeine dissolution

I am looking to add caffeine powder in pure form to water that has a pH level of 7 or higher. What would the pH level be if I do this? Is Caffeine itself acidic?
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1answer
2k views

How could chlorine dioxide be stabilized in aqueous solution?

There is a water-based mouthwash product which is advertised as having the ingredient "stabilized chlorine dioxide." The only other listed ingredients are trisodium phosphate and citric acid. I assume ...
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1answer
2k views

Hand Sanitizer Chemical Changes

I keep a bottle of hand sanitizer on my desk at work, as I touch a lot of things throughout the day. When I used it yesterday, a bit must've been left in the pump track or opening. So I was about to ...
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1answer
1k views

Get the molar mass of an unknown liquid in a dissolution

A dissolution has $10$g of some unknown liquid and also $90$g of water. The freezing point of this dissolution is $-3.33^\text{o}$C. What is the molar mass of the unknown liquid in g/mol? Alright....
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1answer
103 views

Why are chlorides, sulfates, and bicarbonates of Ca and Mg solely responsible for the hardness of water?

When soap is dissolved in water - irrespective of the anion - $\ce{Ca^2+}$ and $\ce{Mg^2+}$ form precipitates. Why are just chlorides, sulfates, and bicarbonates the only specie considered as "...
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1answer
501 views

At what temperature will 6 grams of KMnO4 saturate 100 grams of water

I am trying to obtain more $\ce{KMnO4}$ from less amount by crystallization method. If I got the temperature I would easily make the desired amount. If I am choosing the wrong method, please tell me ...
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1answer
76 views

Solutions of several salts

What happens when you have a solution of a salt, and then try to dissolve another salt in that solution? I know about the common ion-effect etc, but how do you solve problems like this: How much AgCl ...
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1answer
67 views

Weight Percent of Solutions Given Without Units

I have been performing haloform reactions using sodium hypochlorite. The most available source is common household bleach, which is a solution of $\ce{NaClO}$ in water. The bottles invariably give a ...
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1answer
61 views

Why “RCA clean” solution has to be prepared every time (and not stored long-term)?

"RCA clean" solution is a 5:1:1 mixture of DI water, ammonium hydroxide and hydrogen peroxide. Why the ready 5:1:1 solution is not stored for long term, but instead has to be prepared each time ...
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2answers
843 views

Basis for the hydrophobic effect?

I'm confused about why hydrophobic molecules, which do not have high polarity, would have a tendency to attract and cluster with themselves. It is easier to understand the hydrophilic as long as one ...
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1answer
1k views

Why does pouring soda slowly and smoothly seem to keep more of the carbonation?

So, I caught myself gently pouring a can of soda into a cup of ice (making sure that there was room for air to move through so the stream of soda from the can to the cup was consistent and even) ...
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1answer
2k views

How to separate sodium iodide dissolved in water?

Am fairly new to chemistry and apologize if the question and the description are too vague.If you think I lack basic background knowledge to deal with something like this, please point me to a ...
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2answers
7k views

Why is sodium sulfate a neutral salt [duplicate]

When I have a solution of $\ce{Na2SO4}$, the sodium sulfate should ionize: $$\ce{Na2SO4(aq) -> 2Na+(aq) + SO4^{2-}(aq)}$$ In my mind, the sodium ions should just float around, but because $\ce{...
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2answers
35k views

Does dissolving salt in water change the pH?

I am particularly interested in the effect or lack of effect of dissolved NaCl in regards to pH in water. It would be interesting also if anyone has any insight for other salts and their effects. ...
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2answers
6k views

Storage life of 3% hydrogen peroxide

I am using 3% hydrogen peroxide for a series of operations, and the common practice is to prepare it on-site from 30% hydrogen peroxide and saline. This is time consuming and somewhat more prone to ...
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1answer
2k views

Why the “Diverse Ion Effect” increases Ksp?

I've read in chemwiki about the diverse ion effect. Assuming I have an aqueous solution of $\ce{NaCl}$ and an associated $K_\mathrm{sp}$. If I add $\ce{KI}$ there is an associated $K_\mathrm{sp}'$ for ...
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1answer
77 views

Raise the pH of a solution and prevent build up of carbonates

I need to raise the pH of a solution so the easiest approach is to add alkali hydroxides (NaOH, KOH, etc). But as most of you know, the CO$\ce{_2}$ in the air can react with these hydroxides to form ...
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1answer
3k views

How to calculate concentrations in a diluted mixture of multiple solutions?

I have a homework problem as follows: A solution was prepared by mixing $25.0\ \mathrm{mL}$ of $0.208\ \mathrm{M}$ $\ce{Fe(NO3)3}$ and $4.50\ \mathrm{mL}$ of $0.00190\ \mathrm{M}$ $\ce{KSCN}$ and ...
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0answers
93 views

How can I measure the amount of CO2 in grams in a known volume of soda based on its weight?

We have a soda machine that can fill either still water or soda. In both cases the amount is 400 ml in the beaker, but the soda weighs a little less. How can we use the volume X = 400 ml and the ...
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1answer
291 views

Does precipitated copper carbonate contain impurities

I recently performed a double replacement reaction between copper sulfate and sodium carbonate to yield copper carbonate as a precipitate. I then filtered the precipitate, but I noticed that the ...
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0answers
578 views

What results from combining monopotassium phosphate, magnesium sulfate and calcium nitrate?

If I mix monopotassium phosphate, magnesium sulfate, and calcium nitrate together in aqueous solution, what chemicals will result? Are these safe to combine (i.e. any toxic gases, etc.)? I thought ...
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0answers
442 views

acids, bases, salts, etc

All the chemical compounds can be categorized as acids, bases, and neutral compounds. There are different theories, namely Arrhenius Theory, Brønsted-Lowry Theory, Lewis Theory, which define the ...
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1answer
3k views

Oxidation of acetic acid in wine?

When wine is exposed to oxygen, acetic acid forms because of an oxidation reaction. The wine then loses acetic acid. Why? Is it because it is oxidised itself to form carbon dioxide?
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2answers
621 views

Is there a soluble salt, or compound that when dissolved in water results in a solution with density less than pure water?

Generally water soluble salts tend to 'fit between' the molecules of water such that the volume of the resulting solution does not increase much relative to the volume and added mass of the salt. So ...
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2answers
11k views

Solution for storing a glass electrode

What kind of storage solution is required for a glass electrode? Is 3 M $\ce{KCl}$ sufficient for this purpose? If so, what is the approximate pH of that solution (the solution I use presently has a ...
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1answer
2k views

Why are the reactants in the solubility product constant multiplied by their coefficients and raised to the power of their coefficients?

It is probably easiest for me to explain the question in an example. Consider the following chemical reaction: $\ce{MgF2(s) -> Mg^{2+} (aq) + 2F- (aq)}$ Plugging this into the formula for the ...
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1answer
8k views

What happens to iron(III) sulfate (ferric sulfate) in aqueous solution?

Iron(II) sulfate (ferrous sulfate) is a salt that, in an aqueous solution, dissolves and yields $\ce{Fe^{2+}(aq)}$ and $\ce{SO4^{2-}(aq)}$. It then decomposes to ferric sulfate shortly thereafter. ...
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0answers
165 views

Alternative to water as solvent for lithium metaborate?

I want to prepare a sample of lithium metaborate ($\ce{LiBO2}$) and need to dissolve it for this purpose. The only solvents I found so far are water and ethanol. In ethanol, one cannot dissolve ...
14
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1answer
7k views

Why does Mg react vigorously in NaCl solution and less so in water?

When you put $\ce{Mg}$ into water a few $\ce{H2}$ bubbles appear. But when you put $\ce{Mg}$ into a $\ce{NaCl}$ solution there is a vigorous release of $\ce{H2}$, why is this and what reactions are ...
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1answer
182 views

Do ion-exchange resins soften water through a kinetic equilibrium process?

I searched a lot for this and couldn't find any answers. Is water softening a purely ratio-based equilibrium process, ie, more $\ce{Na+}$ cations on resin than there are $\ce{Ca^2+}$ cations in the ...
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1answer
17k views

How to Convert Sucrose to Glucose and Fructose

If you have some sort of sports drink that contains sucrose, how would you take that sucrose and break it down into its components, glucose and fructose? I know that sucrose + water will break it ...
7
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1answer
632 views

Can I equalise osmotic pressure using two different solutes?

I understand that there is a pressure gradient between an aqueous solution, e.g. salty water, and, say, pure water due to osmosis. My question is, is it possible to match or almost match, the osmotic ...
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5answers
7k views

Produce CuCl2 from CuSO4

I have a large amount of copper sulfate available and I am interested in obtaining copper chloride from it. What is the easiest way to do so? I have considered mixing an aqueous solution of copper ...
4
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1answer
5k views

What is the lethal dose ( LD50 ) of coffee?

Of course, there are many types of coffee, so I would like a range of lethal dose amounts for the average human, from the mildest of lattes to the most hardcore of espressos. Pure caffeine's lethal ...
2
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0answers
127 views

Why does solvation release energy? [duplicate]

Whether dissolving acids and salts is exothermic or endothermic, depends on the lattice and solvation energy. Breaking bonds in the lattice requires energy and is endothermic - that is clear. However, ...
5
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1answer
929 views

Why is glycol used as an antifreeze?

Lowering of the freezing point on adding a solute is a colligative property of solutions, it doesn't matter what the nature of the solute is (of course we have to assume ideal solutions). So when it ...
2
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0answers
170 views

If both nitric acid and nitrate ion are stabilised through resonance, what makes the nitrate ion more stable in aqueous medium?

If both nitric acid and nitrate ion are stabilised through resonance, what makes the nitrate ion more stable in aqueous medium? Can the same argument be applied to nitrous acid and nitrite ion in ...
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1answer
4k views

Why does hydrogen phosphate act as a base?

Let's look at question c: a) Write a balanced equation for the reaction. $$\ce{2 NaOH + H3PO4 -> Na2HPO4 + 2 H2O (l)}$$ b) When some crystals of $\ce{Na2HPO4}$ were dissolved in water, ...
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1answer
685 views

Are concentrated salt solutions stable over time?

I have to use dilute salt solutions incredibly frequently, and it takes valuable time to make them from pure reagents every time I need them. Are concentrated salt solutions fairly stable over time? ...
2
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1answer
77 views

Is ingesting water during swimming harmful?

Sometimes I feel the water in the pool is heavily chlorinated. However it is impossible for me to swim without ingesting some water. I am only a learner but even advanced swimmers do concede that they ...
2
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1answer
189 views

What makes cola efficient as a rust remover?

I actually tested submerging a bunch of old rusty knives blades in a cup of plain cola for a few days not expecting much. To my amazement the myth held true, coke is a really good rust remover. So ...
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1answer
2k views

What are the active ingredients of shampoo, and how do they work?

After seeing one too many TV commercial about the fantastical properties of different high-profile shampoo products all "with documented effect" it suddenly struck me that I never actually researched ...
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1answer
752 views

Solubility when multiple salts are involved

Calculate the solubility of $\ce{AgCl}$ ($K_{\mathrm{sp}} = 1.6\times10^{-10}$) in $100.0~\mathrm{mL}$ of $4.00\times10^{-3}~\mathrm{M}$ calcium chloride. The stated answer is: $2.0\times10^{-8}~\...
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2answers
1k views

Can I successfully use a humidifier to distribute caffeine to wake someone up without the usual morning drowsiness?

Would I have any success putting coffee in a humidifier? Or perhaps water mixed with caffeine powder? So I could wake up without a jolting alarm clock, feeling like I already had a cup of coffee? I ...
1
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1answer
155 views

Is NaCl in water considered “solution” despite of NaCl's having some precipitation?

Is $\ce{NaCl}$ in water aqueous? For a certain amount of $\ce{NaCl}$, it can dissolve in water but if you add more $\ce{NaCl}$ it can't dissolve any more. So, if in a certain reaction $\ce{NaCl}$ is ...
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2answers
2k views

difference between solving and dissolving something

What is the difference between the terms 'solve' and 'dissolve'? Up until now I have used the two terms interchangeably, not having any sound scientific definitions for each. I have thought them both ...
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1answer
194 views

Hydration number: Carbonic acid in water

Carbonic acid ($\ce{H2CO3}$) is known to be soluble in water, and that this particular compound is unstable, so much so that according to the 2014 article from Berkeley Lab: New Insights on Carbonic ...

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