Questions tagged [aqueous-solution]
For questions relating to compounds dissolved in water and resulting reactions and acid-base equilibria.
1,119
questions
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0answers
23 views
Gas/solid to aqueous reactions [closed]
In my homework I have seen reactions like HCl(g) -> HCl(aq) or AlCl3(s) -> AlCl3(aq)
How does this work? Shouldn't there be some source of water in the reactants to form an aqueous compound?
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1answer
52 views
Solubility of nitrogen dioxide in sodium hydroxide
I know $\ce{NaOH}$ can absorb $\ce{NO2}$, but I could not find any data of solubility of $\ce{NO2}$ in $\ce{NaOH}$ at room temperature and atmospheric pressure.
I am trying to figure out how much NaOH ...
3
votes
1answer
79 views
Reaction between hydrobromic acid and sodium borate
Write the reaction for a a sodium borate solution being titrated by hydrobromic acid, assuming sodium borate is represented by $\ce{Na3BO3(aq)}$.
I think this is a simple double replacement reaction:
...
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0answers
30 views
How can one measure instantaneous ionisation ratio of a weak electrolyte? [closed]
Trying to get information about ionization ratio of weak electrolyte, led me to a few page with information about how to calculate it, but this will give me a static equilibrium answer. I'd like to ...
0
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0answers
14 views
how dilute should the solution be for a noticeable enough colligative property such as relative lowering in vapor pressure?
I was mixing soup powder with boiling water today and noticed the vapors coming from the water suddenly vanish; seemed like the powder being non volatile decreased the mole fraction of water in the ...
2
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0answers
99 views
Why do we assume that the successive deprotonation of a polyprotic acid happens when only the previous deprotonation has reached equilibrium?
The steps for finding the concentration of the species at the equilibrium of polyprotic acid are as given in this book in section $10.16$ and illustrated on the next page. I have three questions, but ...
2
votes
1answer
25 views
Is a diluted aqueous solution of sodium hypochlorite more stable than a concentrated solution, all else being equal?
On the Clorox website, they recommend that you dilute bleach (NaOCl) in water prior to use for disinfection. They say that you should make a fresh solution each time you need to use it, adding: “Don’t ...
1
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0answers
29 views
How is formula for mean ionic activity derived from its constituent activities?
I spent hours in order to understand the following - but without success:
At many places the mean ionic activity coefficient for the reaction
$$\ldots \rightarrow \nu_A A^{z_A+} + \nu_B B^{z_B-}$$
...
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votes
1answer
37 views
How much salt in a cup of water would it take to neither hydrate nor dehydrate the average person? [closed]
I don't know a lot about chemistry, and this question came up during lunch with my friend. I was interested in this question so I thought I could ask here. Sorry if I didn't use the right tags.
2
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0answers
31 views
Maintaining our supersaturated oceans
Supersaturates solutions can be unstable and decay beautifully once a seed crystal is introduced.
Our oceans near the surface are supersaturated with respect to calcium carbonate. This map shows the ...
0
votes
2answers
60 views
What might cause overestimated measured pH value of sodium hydroxide solution pumped with carbon dioxide?
I tried an experiment at home where I had a $\ce{CO2}$ tank pumping $\ce{CO2}$ into a solution of $\pu{28 g}$ sodium hydroxide in $\pu{200 ml}$ water. The initial $\mathrm{pH}$ was $11.24.$
I expected ...
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1answer
62 views
Mixing hydrogen peroxide and sodium hydroxide doesn't lead to sodium peroxide anymore [closed]
I've been using same bottle of hydrogen peroxide and same bottle of 50 % of sodium hydroxide to make sodium peroxide for a month now. You could see the presence of sodium peroxide in the solution ...
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votes
1answer
66 views
Predict whether a reaction is likely to occur. If so, write a net ionic equation [closed]
a) $\ce{AgNO3(aq) + CuCl2(aq) -> }$
So the first step is to combine the inners and outers.
So I have $\ce{AgCl}$ and $\ce{CuNO3}$
I know $\ce{NO^-_3}$ has a -1 charge so then wouldn't $\ce{Cu}$ ...
0
votes
1answer
57 views
Hydrated electrons produced by radiation vs electrons from electrostatic charge: are they equally reactive?
One of the species generated in water or aqueous solutions by the ionizing radiations are free electrons that quickly become "hydrated" or "aqueous electrons" (see for example this ...
0
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0answers
35 views
Waste management of hazardous solvents
How should one safely dispose of chemicals like dichloromethane, toluene or acetone that were mixed with water?
Is the water contaminated to a degree that it needs also treatment?
For example ...
0
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0answers
28 views
How to prepare a solution of Ferrous Iron?
I need to prepare a solution of Ferrous Iron (Fe2+). This solution will be used to test a water filtration system by simulating the Ferrous Iron that is sometimes present in well water. The system is ...
0
votes
1answer
36 views
Why is the enthalpy of solution of hydrated calcium chloride positive?
My book says that the enthalpy of solution of anhydrous calcium chloride is negative because it produces hydrated calcium chloride. But when hydrated calcium chloride is dissolved in water, the ...
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votes
1answer
34 views
Do coordination complexes with stronger ligands form more stable complexes?
I read that chelate complexes generally are more stable than monodentate complexes. However, I noticed that in the case of $\ce{[Fe(CN)6]^3-}$ and $\ce{[Fe(en)3]^3+}$, this is not observed as the ...
1
vote
1answer
114 views
Method to remove impurities from acetaminophen synthesis experiment
I'd like to know about impurities from acetaminophen synthesis experiment. Are there any impurities produced by oxidation of p-aminophenol? If there is any impurity produced by oxidation of p-...
0
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0answers
33 views
Copper powder from aqueous copper sulfate solution help
I’ve been wanting to make copper powder for some homemade pyrotechnics. When placing an iron object in a copper sulfate solution, copper powder is produced. However, sooner or later, the reaction ...
3
votes
0answers
24 views
Can Chlorhexidine Gluconate (CHG) be used for disinfection of medical device (e.g. of polyethylene material)? [closed]
Chlorhexidine is commonly used as a skin antiseptic, hand disinfectant, endodontic irrigant etc. It possess antibacterial and antifungal properties, and is considered low toxicity when used in low ...
0
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1answer
117 views
Dextrose equivalent values (DE) of the most common sugars
What are the dextrose equivalent values (DE) of lactose, and other common sugars?
Some data like the values for sucrose (0), maltodextrin (x<20), maltose (52), and glucose (100) can be found at ...
1
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0answers
35 views
Aqueous glucose solution concentration computation
The question in my worksheet is as follows:
You dissolve $\pu{1.451 mol}$ of glucose in water to a volume of $\pu{250 mL}$. The mass of the glucose is $\pu{261 g}$ and the molecular weight $\pu{180....
0
votes
1answer
30 views
Acid dissociation constant calculated from the ionization percentage
The question goes like this:
An acid (HX) is 25% dissociated in water. If the equilibrium concentration of HX is $\pu{0.30 M}$, calculate the value of $K_\mathrm{a}$.
So I tried as follows:
if I ...
1
vote
0answers
32 views
How do two species from the same buffer system have different pKa values? [closed]
$$
\begin{array}{lr}
\hline
\text{Reagent}~(\pu{0.1 M}~\text{solutions}) & \mathrm{p}K_\mathrm{a} \\
\hline
\text{Ammonia} & 9.25 \\
\text{Acetic acid} & 4.75 \\
\text{Ammonium chloride} &...
1
vote
2answers
56 views
If a company advertises a solution as 20% on their web-site, will it be 20% w/w?
I am trying to buy some ammonia solution from a company and I have found the product I want but the product particulars just tell me it's 20%. They don't say if it's 20% w/w or w/v? Their technical ...
2
votes
1answer
90 views
Relation between standard silver-silver chloride electrode potential and solubility product of silver chloride
I learned that $E^\circ_\ce{Cl^-|Ag,AgCl}, E^\circ_\ce{Ag^+|Ag}$ and $K_\mathrm{sp}$ of $\ce{AgCl}$ are related as
$$\boxed{E^\circ_\ce{Cl^-|Ag,AgCl} = E^\circ_\ce{Ag^+|Ag} + \frac{RT}{F}\ln K_\mathrm{...
3
votes
1answer
119 views
Why is hydrogen peroxide acidic in aqueous solution?
This seemed like a trivial question to me... until I began to think about it.
The "usual" criteria for greater acidity are larger sizes of the atom attached to the acidic proton within the ...
1
vote
1answer
84 views
Is this true for conductivity of mixture of two solutions equal to the sum of conductivities of each solution?
Suppose $\ce{Na2SO4}$ has a conductivity $\pu{2.6 \times 10^{-4} S cm-1}$ and on mixing $\ce{CaSO4}$ to saturation, the conductivity becomes $\pu{7.0 \times 10^{-4} S cm-1}$.
So, Is the conductivity ...
1
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1answer
33 views
Will Sodium Polyacrylate (SAP) absorb the gas from liquid ammonia?
I'm considering using sodium polyacrylate grains to absorb spills of a relatively strong Ammonium Hydroxide solution. Will the SAP (super absorbent polymer) only absorb the water, and in effect make ...
6
votes
1answer
144 views
Numerically solving chemical equilibrium equations
Here are chemical equilibrium equations:
$\begin{cases}
\mathbf{N}^\text{T}\mathbf{X}+\mathbf{C}=\mathbf{Y}\\
\mathbf{N}\ln\mathbf{Y}=\ln\mathbf{K}
\end{cases}$
Here $\mathbf{C}=\begin{pmatrix}c_1\\...
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votes
1answer
59 views
How exactly does a buffer made up of a weak acid and its conjugate base work upon addition of hydroxide ions? [duplicate]
Consider a buffer solution containing a weak acid and its conjugate base ($c_\mathrm{total} = \pu{0.1 mol L-1}$):
$$\ce{HA <=> H^+ + A^-}$$
When $\ce{H+}$ ions are added (from a strong acid), ...
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votes
1answer
206 views
Calculating molarity of iodine solution after reaction
I made an iodine solution referring to the methodology provided in this link:
https://www.thoughtco.com/vitamin-c-determination-by-iodine-titration-606322
$$\ce{KIO3 + 5KI + 3H2SO4->3I2 + 3H2O + ...
2
votes
2answers
90 views
How do you achieve phase separation of a methanol / chloroform solution?
If I'm washing a methanol solution with chloroform, can I just add water in a 1:1 mixture with the methanol and expect it to break? Do I need to do anything else to cause the aqueous phase to separate ...
1
vote
1answer
111 views
Calculating pH of aqueous ammonium hydrogen sulfide solution
I was doing the following question yesterday:
Calculate the pH of a $\pu{0.1 M}$ solution of $\ce{NH4HS}$, given $\mathrm{p}K_\mathrm{b}$ of $\ce{NH3}$ is $4.74$, and $\mathrm{p}K_\mathrm{a1}$ and $\...
8
votes
2answers
459 views
Looking for caffeine partition coefficients
As part of a project, I'm looking to carry out a liquid-liquid extraction of caffeine from an aqueous phase to an organic phase, using dichloromethane or ethyl acetate.
So I'm looking for the ...
1
vote
1answer
44 views
Understanding the Osmotic Pressure formula
$$\Pi = iMRT$$
Can this be rewritten as $\Pi = ORT$ where $O =$ osmolarity? The only reason I ask is because my book doesn’t talk about the relationship between osmolarity and molarity, but I came ...
16
votes
1answer
1k views
Why does the graph of the electrical conductivity of sulfuric acid/water solutions have this knee in the ~85%-~92% range?
This answer to an earlier question regarding the electrical conductivity of sulfuric acid provides a graph showing the conductivity of sulfuric acid/water mixtures ranging from 0% to 100% sulfuric ...
3
votes
1answer
61 views
pH meter mechanism - connecting potential differences
This question was asked here: pH probe bulb - what is happening within the glass? and How does a pH glass electrode work?.
But, the mechanism remains unanswered. How does a potential difference ...
7
votes
1answer
68 views
Definition of dissolve and the state label (aq) in chemical equations
I am confused with the meaning of "(aq)" in chemical equations, and the meaning of "dissolved". What is the actual meaning it is supposed to convey?
For instance, in the document &...
22
votes
3answers
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Is "Sulfuric acid... makes a poor electrolyte... very little of it will dissociate into ions" really true? What does that actually mean?
While researching chromate conversion coating for edits to this answer in Space Exploration SE, I came upon the following passage in Corrosion Resistance of Stainless Steel to Sulfuric Acid
Sulfuric ...
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votes
1answer
64 views
How are acids in aqueous solution able to react again after reacting with water?
I hope to clear up some confusion I have about acid-base reactions in aqueous solution.
Based on the Bronsted-Lowry definition of acids, I know acids donate protons. In water, a strong acid should ...
3
votes
1answer
163 views
How to determine the equivalents of OH- in a titration curve
How does one go about determining the equivalents of $\ce{OH-}$ needed for the titration of a weak acid. For example here is the titration curve for Aspartate:
Why is the equivalents for $\mathrm{p}...
0
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0answers
58 views
Which method has the highest yield of calcium sulfate?
I'm not sure which of following two methods will give better yields for $\ce{CaSO4}$:
A. Add dilute $\ce{HNO3}$ to $\ce{CaCO3}$, followed by dilute $\ce{H2SO4}$; or
B. Titrate aqeuous calcium ...
-1
votes
1answer
145 views
Why does acetate ion react with water? [closed]
When NaCl is added to water, it dissociates into $\rm{Na^+}$ and $\rm{Cl^-}$. The newly formed $\rm{Na^+}$ and $\rm{Cl^-}$ do not react with water.
When $\rm{CH_3COONa}$ (sodium acetate) is added to ...
1
vote
1answer
38 views
Microfiltration for saturated solutions of highly hygroscopic compounds?
Is it possible to pass saturated solutions of compounds with very high solubility through filters with small pores (e.g. passing a saturated aqueous ZnCl2 solution at 90C through a 2mcm glassfiber ...
9
votes
1answer
190 views
Do azeotropic mixtures evaporate proportionally?
Do azeotropes evaporate, without boiling, in proportionate amounts, or does this property describe their behaviour only at boiling point?
Concretely, if 91% isopropyl alcohol/water (by volume, i.e. an ...
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votes
2answers
75 views
will splitting a solution will keep the concentration values (and moles) the same? [closed]
I have this exercise from my H.W:
and I am asked: if we split the solution into 3 different containers equally -
how many moles will the solution have in each container?
will the Cl- concentration ...
5
votes
1answer
116 views
What is the dissociation percentage of a polybasic organic acid at a certain pH?
For my Master's Thesis I am working with the dicarboxylic acid muconic acid $(\ce{H2MA},$ $\mathrm{p}K_\mathrm{a1} = 2.9,$ $\mathrm{p}K_\mathrm{a2} = 4.0).$ It thus dissociates into $\ce{HMA-}$ and $\...
1
vote
1answer
57 views
Effect of side reactions on galvanic cell using iron rod as anode and sodium chloride as salt bridge
We just made a galvanic cell on a chemistry lesson using iron, iron sulfate , copper and copper sulfate.
We used a sponge soaked in $\ce{NaCl}$ solution as the salt bridge. The issue is that we ...
