Questions tagged [aqueous-solution]
For questions relating to compounds dissolved in water and resulting reactions and acid-base equilibria.
1,096
questions
-1
votes
0answers
13 views
Calculating the concentration of ammonia solution [closed]
If 20gm of ammonia gas is dissolved in 1 liter water, then what will be the concentration of the solution?
2
votes
1answer
80 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
69 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 ...
0
votes
0answers
43 views
Would para-aminobenzoic acid exist as a zwitterion or non-ionized at pH 4?
The two $\mathrm{p}K_\mathrm{a}$ values for p-aminobenzoic acid (PABA) are: $\mathrm{p}K_\mathrm{a1} = 2.50$ and $\mathrm{p}K_\mathrm{a2} = 4.8$.
My thought was that at a $\mathrm{pH}$ of 4, the ...
1
vote
1answer
24 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
93 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 $\mathbf{C}=\begin{pmatrix}c_1\\...
-1
votes
1answer
57 views
How exactly does a buffer made up of a weak acid and its conjugate base work upon addition of hydroxide ions? [duplicate]
Consider a buffer solution containing a weak acid and its conjugate base ($c_\mathrm{total} = \pu{0.1 mol L-1}$):
$$\ce{HA <=> H^+ + A^-}$$
When $\ce{H+}$ ions are added (from a strong acid), ...
-2
votes
1answer
54 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
$$\ce{KIO3 + 5KI + 3H2SO4->3I2 + 3H2O + ...
2
votes
2answers
74 views
How do you achieve phase separation of a methanol / chloroform solution?
If I'm washing a methanol solution with chloroform, can I just add water in a 1:1 mixture with the methanol and expect it to break? Do I need to do anything else to cause the aqueous phase to separate ...
1
vote
1answer
91 views
Calculating pH of aqueous ammonium hydrogen sulfide solution
I was doing the following question yesterday:
Calculate the pH of a $\pu{0.1 M}$ solution of $\ce{NH4HS}$, given $\mathrm{p}K_\mathrm{b}$ of $\ce{NH3}$ is $4.74$, and $\mathrm{p}K_\mathrm{a1}$ and $\...
8
votes
2answers
340 views
Looking for caffeine partition coefficients
As part of a project, I'm looking to carry out a liquid-liquid extraction of caffeine from an aqueous phase to an organic phase, using dichloromethane or ethyl acetate.
So I'm looking for the ...
1
vote
1answer
35 views
Understanding the Osmotic Pressure formula
$$\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
722 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
38 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
55 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
2k views
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 ...
-1
votes
1answer
50 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
67 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
votes
0answers
48 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
69 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
37 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
168 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 ...
-5
votes
2answers
47 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
113 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
42 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
40 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
vote
1answer
65 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 ...
5
votes
1answer
201 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
46 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
146 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
votes
0answers
36 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
51 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 ...
0
votes
1answer
26 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
vote
1answer
129 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
204 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 ...
1
vote
3answers
49 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
votes
0answers
27 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
325 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}$$
If $\ce{NO}$ and $\ce{NO2}$ are formed in 2:3 ratio, what is coefficient of $\ce{...
1
vote
1answer
115 views
Balancing redox reaction of zinc and hot diluted nitric acid
I need to balance the following reaction:
$$\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
votes
0answers
23 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
vote
1answer
34 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
votes
1answer
52 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
vote
0answers
64 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.
$...
-2
votes
1answer
60 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
vote
0answers
49 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
13 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
votes
0answers
22 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
51 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 ...
2
votes
1answer
29 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 ...
