Questions tagged [aqueous-solution]
For questions relating to compounds dissolved in water and resulting reactions and acid-base equilibria.
1,074
questions
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0answers
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does autoionization constant stays the same even if we add HCl and NAOH to water?
in a homework , when im asked to calculate the constant Ka of this reaction :
OH- + H3O+ ===> 2H2O (it is about a titration of a strong base NAOH with a strong acid HCl)
when i dont have the ...
1
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1answer
29 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 ...
-2
votes
1answer
33 views
Phenolphthalein + sodium carbonate and phenolphthalein + sodium bicarbonate [closed]
What would the word equations be for the following two situations?
Initially $\ce{Na2CO3}$ and $\ce{NaHCO3}$ were present as 2 unknown powders, dissolved in water, and phenolphthalein was added to ...
1
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1answer
56 views
Hydration vs Dissolution
While revising Thermodynamics and Thermochemistry from revision material published by Arihant publications I encountered the following mentioned statement.
During dissolution, the physical state of ...
-1
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1answer
29 views
How does the concentration of a liquid increase? [closed]
Here the answer is A, I thought that both solids and liquids had constant concentrations and only aqueous solutions and gasses have changes in concentration. how does adding extra ester increase the ...
5
votes
1answer
170 views
Why is the aqueous solution of KMnO4 slightly basic?
This is in the context of the various changes in oxidation state the permangananate ion can undergo with the variation of the pH of the medium. Besides the cases of strongly basic and strongly acidic ...
0
votes
1answer
39 views
What are counterion effects?
I was reading the following article on wikipedia about Hydroponics
Unlike most nutrients, plants can tolerate a high concentration of the
$\ce{SO4^2−}$, selectively absorbing the nutrient as needed.
...
2
votes
1answer
57 views
Why is Maleic Acid more soluble in water than its trans isomer Fumaric Acid?
My teacher taught me that compounds having intramolecular H-Bonding are relatively less soluble in water as they will not involve in H-Bonding with water appreciably while those able to do ...
0
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0answers
34 views
Osmotic Pressure of Aqueous Solution
The osmotic pressure of an aqueous solution at $25$ Celsius is $92.0$ $kPa$. Calculate the boiling point
of the solution. (Assume that the density of the solution is $1.0$ $g/mL$, ignore the mass of ...
0
votes
1answer
46 views
Phase of reaction between glucose and potassium cyanide to form amygdalin
I'm trying to write a detective-fiction novel, and I was wondering if potassium cyanide reacts with sugar only if the glucose for the amygdalin to form is dissolved in liquid or does it react even if ...
-1
votes
0answers
16 views
How to switch concentration of 30/70 water/ethanol through dialysis? [closed]
I mistakenly dialysed a preparation in ethanol such that it is now 30% water and 70% ethanol. How do i make switch the water/ethanol concentrations (70% water and 30% ethanol) via dialysis again? The ...
0
votes
1answer
20 views
Methanol-water mix freezing points - clarify contradictory online data > 60% w/w?
Extending an exploration of windshield washer-fluid choices to freezing points of methanol-water mixes, all web-sources located agreed to within a couple of degrees from 0-60% w/w, yet above this ...
1
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1answer
73 views
Finding mass percent through molality of potassium nitrate solution
Question
An aqueous $\ce{KNO3}$ solution has a molality of $\pu{4.16 m}$ and a density of $\pu{1.08 g/mL}$. Calculate the percentage by mass $\ce{KNO3}$ of the solution.
My Approach
I know that ...
8
votes
1answer
179 views
pH of an aqueous solution with acetic acid and sodium acetate
An aqueous solution of $\pu{1L}$ contains $\pu{0.2 mol}$ of acetic acid and $\pu{0.2 mol}$ of sodium acetate ($K_\mathrm{a} = 1.8 \times 10^{-5}$). Compute the $\mathrm{pH}$ .
I'm trying to help my ...
0
votes
1answer
56 views
Finding freezing point depression knowing molality and density
The density of a $\pu{7.71 M}$ $\ce{LiCl}$ solution is $\pu{1.1678 g cm-3}$. Calculate the freezing point depression of the solution.
I understand that in order to calculate the freezing point ...
1
vote
3answers
47 views
When an aqueous extract of a substance is said to be administered at a certain quantity, is the quoted mass analogous to one as original substance?
I'm trying to read studies about the possible toxicity of the leaves of some plant often said to possess positive medicinal properties.
In the studies, performed on rats, it is usually said that an ...
0
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0answers
23 views
Is it the solution energy or the reduction potentials (or both) that drives a galvanic cell?
I have received conflicting explanations for why the redox reaction in a galvanic cell occurs.
Explanation 1:
Some say that it occurs because the anodic metal dissolves more easily than the cathodic ...
6
votes
2answers
287 views
Balancing reaction between copper and nitric acid given the ratio of formed nitrogen oxides
Problem
$\ce{Cu}$ reacts with $\ce{HNO3}$ according to the equation
$$\ce{Cu + HNO3 -> Cu(NO3)2 + NO + NO2 + H2O}$$
If $\ce{NO}$ and $\ce{NO2}$ are formed in 2:3 ratio, what is coefficient of $\ce{...
1
vote
1answer
84 views
Balancing redox reaction of zinc and hot diluted nitric acid
I need to balance the following reaction:
$$\ce{Zn + HNO3 -> Zn(NO3)2 + NH4NO3 + H2O}$$
I assigned all oxidation numbers:
$$\ce{\overset{0}{Zn} + \overset{+1}{H}\overset{+5}{N}\overset{-2}{O_3}\...
0
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0answers
22 views
Total concentration conversion
when dealing with waste water and the total values of P, N, C are given in ppm units, what molecular weight is used for converting from ppm to molar?
for Example- what will be 12 ppm of P(T) in Molar ...
1
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1answer
26 views
More ions form pairs when concentration of acid increases, does that decrease the speed of reaction?
Electrical conductivity decreases as an acid becomes more concentrated because more ions form pairs. However, does that affect the speed of reaction of the acid as there is a smaller concentration of ...
0
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1answer
47 views
How to make silicic acid, potassium silicate or calcium silicate?
I am a student of tropical agriculture. I am taking the class of agronomic chemistry and plant nutrition. I want to make use of silicate source I have at home for e.g. zeolite, wood ashes, ...
1
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0answers
57 views
Substituting K2CO3 for KOH in Soap
Wood water obtained by running water through hardwood ashes has a high quantity of $\ce{K2CO3}$, historicaly this was called lye. Yet soap recipes today seem to use $\ce{KOH}$ or $\ce{NaOH}$ as lye.
$...
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1answer
54 views
Notation for inclusion of water in a dissolution equation
Earlier I had a student come by wanting to know how to show the dissolution of $\ce{NH4OH}$ in water. I would think we would just write it: $$\ce{NH4OH(aq) <=> NH3(aq) + H2O(l)}$$ I say this as $...
1
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0answers
46 views
Calculate concentrations of ions after acid-base reaction given volumes and concentrations
A $\pu{35.0 mL}$ of $\pu{4000 ppm}$ $\ce{HCl}$ solution is mixed with $\pu{45.0 mL}$ of $\pu{0.1025M}$ $\ce{NaOH}$ solution. Assume volumes are additive.
$$\ce{NaOH(aq) + HCl(aq) -> NaCl(aq) + H2O(...
5
votes
1answer
1k views
Can you meassure a negative pH value with a pH meter?
I was checking the $\mathrm{pH}$ of $\pu{1 M}$ chromic acid solution, and I got its $\mathrm{pH}$ around -1.7. Yet, $\mathrm{pH}$ of $\pu{0.4 M}$ solution was around -0.6. Could these values be ...
0
votes
0answers
12 views
What is an effective coagulant/flocculant for an acidic solution?
The acidic solution is a mixture of dissolved ammonium sulfate and mono-ammonium phosphate (pH about 4.5-4.8) along with an inorganic sludge with a similar consistency to clay I am looking to remove ...
0
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0answers
21 views
Equilibrium of zinc ion with ammonia
In my chemistry lab, we are testing the amphoteric properties of this metal. I understand zink can react with an acid or a base to form different compounds in solution based on pH. In one part of the ...
0
votes
2answers
49 views
How to model 98% ethanol solution concentration graph over time
İ want to plot a graph of ethanol solution concentration over time .So we know that alcohol evaporates quickly in open air but is there a time when the rate of evaporation mathces that of water and ...
0
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0answers
20 views
How to explain why the boiling point of the aqueous solution of a non-volatile solute increases
I have the following graph:
with the following expression for the chemical potential variation:
I need to explain why the boiling point of the aqueous solution of a non-volatile solute increases, ...
2
votes
1answer
27 views
Would ionic conduction be halted by shielding at the electrodes?
I've done this experiment myself and seen it front of my eyes. Set up a basic circuit with a battery, an LED, and connect the circuit with a salt-water solution and copper wire. The LED lights up.
If ...
1
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0answers
36 views
Green deposition on the anode after electrolysis of sodium bicarbonate solution in tap water
I use $\pu{12 V}$ battery with copper wires and tap water with $\ce{NaHCO3}$ dissolved in it. I connected the battery and everything went as expected but after 5 minutes bubbling stopped. I took out ...
-2
votes
1answer
66 views
Is mixture of ammonium hydroxide and ammonium nitrate a buffer solution? [closed]
Is a mixture of $\ce{NH4OH}$ and $\ce{NH4NO3}$ a buffer solution?
I have seen some examples with $\ce{NH4OH}$ and $\ce{NH4Cl}$ but never $\ce{NH4NO3}$.
-4
votes
1answer
34 views
Grams of solution of magnesium chloride given molarity of chloride ion [closed]
To make 100. mL of a solution that is 0.25 M in chloride ion, how many grams of magnesium chloride would you need to dissolve?
I had a few different approaches to this, but my most immediate thought ...
1
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0answers
85 views
Physical Chemistry: Specifically the Dissolution of Carbonates
Please note this question is different to the other that keeps being mentioned. That one is about the concentration of just $\ce{HCO3-}$ when no $\ce {pH}$ was given.
Whereas, in this one I am trying ...
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votes
2answers
48 views
Milliliters of NaBr when changing molarity [closed]
I was very confused by this problem. I was able to get the molarity, but I wasn’t certain how to go from there:
If $\pu{2.60 g}$ of $\ce{NaBr}$ is dissolved in enough water to make $\pu{160.0 mL}$ of ...
0
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0answers
18 views
Why is the Ag+ concentration in a beaker fixed in the reaction between excess AgCl (s) and KI (aq) from the start? [duplicate]
This arises as a sub-question for the following question: Calculate the concentration of I- in a solution obtained by mixing 0.10 M KI with an excess of AgCl(s).
I tried to look at How does addition ...
3
votes
1answer
47 views
Why is hydrated beryllium ion acidic?
The beryllium ion, $\ce{Be^{2+}}$, forms the aquo complex $\ce{[Be(H2O)4]^{2+}}$. According to LibreTexts, this complex is acidic in solution: $$\ce{[Be(H2O)4]^{2+} + H2O -> [Be(H2O)3OH]+ + H3O+}$$
...
0
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2answers
144 views
How does addition of AgCl affect concentration of iodide in KI solution?
In a mixture of $\ce{AgCl(s)}$ and initial $\pu{0.10 M}$ $\ce{KI}$, what is the $[\ce{I-}]$ after the reaction proceeds?
Disclaimer: This is not a graded assignment, but rather a problem I'm trying to ...
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votes
1answer
42 views
How to calculate how much weak acid would dissociate in water?
So I know water has a pH of 7. If we add 0.1 mol of a strong acid inside 1 liter of water, it WILL fully dissociate into 0.1 mol of A- and 0.1 mol of H+ thus making the pH of the solution 1.
But what ...
3
votes
0answers
34 views
Can there be an aqueous solution with a convex meniscus?
This question is motivated by a quote from a TV show:
A detective is looking at a small vial (really a glass tube) that supposedly contains poison. Then the detective says:
You don't have to take AP ...
0
votes
1answer
140 views
Universal symbols for molar mass, molarity, and molality
This is a really basic (perhaps trivial) question, but I just want to confirm:
What are the SI symbols for molar mass, molarity, and molality? For molality and molarity, there is a difference, but I’...
0
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0answers
25 views
Adding aluminum sulfate to neutralize an aqueous solution of sodium silicate with pH of 12.6
How much aluminum sulfate do I need to add to an aqueous solution of sodium silicate to neutralize the solution (pH from 12.6 to 7)?
For a water treatment school project, we remove sodium silicate ...
2
votes
1answer
102 views
How to calculate molar concentration from equilibrium equations with no initial concentration given?
I have the equations:
\begin{align}
\ce{CO2(g) + H2O(l) &<=> H2CO3(aq)} &\quad K_1 &= 10^{-1.47} \tag{1}\\
\ce{H2CO3(aq) &<=> H+(aq) + HCO3-(aq)} &\quad K_2 &= 10^{-...
3
votes
1answer
94 views
Why does green ferrous sulfate solution change color to yellow upon addition of hydrochloric acid?
I was demonstrating the formation of $\ce{Fe(OH)2}$ precipitate at school when the light green $\ce{FeSO4}$ I was using reacted with dil. $\ce{HCl}$ turned yellow. This only happened with dil. $\ce{...
0
votes
0answers
42 views
pH of an aqueous solution of Mg2+ kept rising above that of clean water. What's going on?
In a recent inorganic chemistry lab session, we tested the pH of various ions in water. The water turned out to be on the acidic side (5.5 with $\mathrm{pH}$-paper, 5.59 with $\mathrm{pH}$-meter). A ...
5
votes
0answers
116 views
What pH value of 1M sodium crotonate solution supposed to be?
I need to prepare the $\pu{1M}$ solution of sodium crotonate, however, I don't have one in lab, but I do have sodium hydroxide and crotonic acid.
Thus, I calculated that for $\pu{100 mL}$ of $\pu{1M}$ ...
0
votes
1answer
32 views
Disparity between LeChatelier's Principle and Solutions
Let's say that there is a solution
$\ce{Na+(aq) + Cl-(aq) <=> NaCl(s)}$
If the above solution is at equilibrium we can say that it is saturated and hence no more Sodium Chloride will dissolve. ...
0
votes
1answer
51 views
Why is the solution of ammonium bifluoride more acidic than aqueous ammonium fluoride?
At low concentrations of aqueous $\ce{NH4HF2}$ $(w = 1–2\,\%)$ $\mathrm{pH}\approx 3.$
But aqueous $\ce{NH4F}$ $(w = 20–40\,\%)$ has $\mathrm{pH}\approx 7.$
Yet the equilibria of
$$
\begin{align}
\ce{...
1
vote
1answer
73 views
Dissociation equilibria of ammonium bifluoride in water
Ammonium bifluoride or ammonium hydrogen fluoride is a salt of a weak base and a weak acid.
The weak acid is because the second equilibria of $\ce{HF}$ written as:
$$\ce{HF + F- <=> HF2-}$$
and ...
