All Questions
Tagged with equilibrium aqueous-solution
128
questions
2
votes
1
answer
67
views
Does solubility product dictate predominant precipitate from the solution with several ionic compounds?
While removing temporary hardness through boiling, magnesium bicarbonate will give $\ce{Mg(OH)2}.$ $\ce{Mg(OH)2}$ predominates over $\ce{MgCO3}$ as the solubility product $K_\mathrm{sp}$ of $\ce{Mg(OH)...
1
vote
1
answer
107
views
Why does balancing the oxidation of dichromate(VI) to chromium(III) require six iron atoms?
The problem:
Balance the following chemical equation using oxidation numbers:
$$ \ce{Fe^2+ + Cr_2O_7^2- -> Fe^3+ + Cr^3+} $$
What I have tried:
$$\ce{\overset{+II}{Fe}^{2+}(aq) + \overset{+VI}{Cr}...
2
votes
2
answers
316
views
My textbook writes hydronium ion as [H(H2O)]+, is this correct? [closed]
[...] Thus, it bonds to the oxygen atom of a solvent water
molecule to give trigonal pyramidal hydronium ion, $\ce{H3O^+}$ $\ce{\{[H (H2O)]^+\}}$ (see box).
In this chapter we shall use $\ce{H^+(aq)}$ ...
0
votes
1
answer
475
views
Why does balancing the reduction of dichromate(VI) to chromium(III) require four water molecules among the products?
Problem
Balance the following chemical equation using oxidation numbers:
$$\ce{Cr2O7^2–(aq) + HNO2(aq) –> Cr^3+(aq) + NO3–(aq)}$$
Solution (in Swedish)
$$\ce{\overset{+VI}{Cr}_2O7^2–(aq) + H\...
2
votes
4
answers
172
views
How can the Kw of water be constant?
I know in neutral solution, $\ce{[H+]}= \ce{[OH-]}= \pu{1.0 x 10^-7}$.
However, let’s say I add an acid like HCl. This will increase $\ce{[H+]}$, therefore it’s no longer $\pu{1.0 x 10^-7}$, but is ...
1
vote
1
answer
157
views
Solubility of SrF2 in aqueous solution of NaF
This might be really simple question but I have no idea how to proceed to solve such kind of question.
The solubility product of $\ce{SrF2}$ in water is $\pu{8E-10}$. Calculate its solubility in 0.1M ...
2
votes
1
answer
103
views
Equilibrium Solubility of CO2 in Aqueous Solution and its Dependence on H3O+ Concentration
The equilibrium solubility of $\ce{CO2}$ in an aqueous solution is given by three chemical reactions:
$$
\begin{align}
\ce{CO2(g) &<=> CO2(aq)}\label{rxn:R1}\tag{R1}\\
\ce{CO2(aq) + H2O &...
-4
votes
2
answers
88
views
Successive deprotonation - how far can it go?
It has been written that among the equilibria of the dissolution of $\ce{SO_2}$ in water, the dissociation of sulphur dioxide into $\ce{HSO_3^-(aq) + H_3O^+(aq)}$ is a complete dissociation. See the ...
0
votes
1
answer
74
views
Why does the reaction of dissolution stop at an equilibrium point? [closed]
The formula for Gibbs free energy is $\Delta G=\Delta H-T\Delta S$.
If Gibbs free energy is negative, the reaction is spontaneous. This also applies to dissolution reactions.
However, we know that ...
3
votes
2
answers
2k
views
Calculate the titer of a solution
I hope this is the right place to ask. We have this exercise without solution
One litre of diluted sodium hydroxide solution (c = 0.15mol/litre) is
to be prepared in the laboratory. The titer from ...
1
vote
1
answer
105
views
What is the maximum number of silver(Ⅰ) ions in one litre of a 0.003 M sodium sulfide solution?
What is the maximum number of silver(Ⅰ) ions that can be present dissolved in one litre of a $\pu{0.003 M}$ $\ce{Na2S}$ solution?
According to my book, silver(I) reacts with sulfide producing $\ce{...
1
vote
0
answers
69
views
Would a container made of sugar eventually dissolve if filled with a sugar-saturated solution of water?
Suppose you had a bottle made of sugar glass, and filled it with water that was already saturated with sugar.
I know that with a fully saturated solution of sugar in water, no additional sugar can ...
-3
votes
2
answers
246
views
Calculate the concentration of HF in aqueous solution of NH4F and NH4HF2 mixture
There is a similar question on this site, but here i have a mixture.
I have a mixture of NH4F (35% weight) and NH4HF2 (8% weight) in water. How do I calculate the weight % expressed in HF? or the ...
2
votes
2
answers
147
views
Find the added volume of HCl so that the ions separate
Suppose we have a 10mL solution that contains 0.02M $\ce{Ag^+}$ and 0.04M $\ce{Ba^{2+}}$. a) Find the necessary volume to be added of $\ce{HCl}$ to separate all the silver. (Assume to be separated if ...
-1
votes
1
answer
114
views
Why phenolphthalein is not completely neutralized in basic solutions? [closed]
Phenolphthalein $(\ce{HIn})$ is slightly acidic. Why doesn't it completely break down into $\ce{H+}$ and $\ce{In-}$ and also reacting with all of the $\ce{OH-}$ ion present, unlike $\ce{NaOH}$ and $\...
1
vote
2
answers
262
views
What is the significance of charge balancing when analysing system speciation (carbonate system given as an example)?
Following on from my previous question and accepted answer, How do I quantify the carbonate system and its pH speciation?, I also calculated a charge balance ($CB$) on the system where $z$ is the ...
4
votes
1
answer
1k
views
How do I quantify the carbonate system and its pH speciation?
I did Environmental Water Chemistry as part of my undergraduate course where we quantified pH-speciation for the full carbonate system and I got it right according to my tutor. My speciation profile ...
1
vote
1
answer
122
views
How to find ion concentrations at various points in a solution that will precipitate multiple insoluble salts?
The solubility product constant of lead (II) iodide is $1.2 \times 10^{-5}$ at 273 K.
The solubility product constant for lead (II) carbonate is $1.5 \times 10^{-13}$ at the same temperature.
50 ...
1
vote
0
answers
305
views
Chemical Equilibrium of the Esterification Reaction Between Propanol and Ethanoic Acid
I am trying to investigate the relationship between temperature and equilibrium constant of the esterification reaction between propanol and ethanoic acid in reflux system, with conc. sulphuric acid ...
0
votes
0
answers
72
views
Finding dissolved amount of base from pH and solubility product
Calculate the amount of $\ce{Mg(OH)2}$ which is solubilized in $\pu{1.25 L}$ of a buffered solution at $\mathrm{pH} = 9.5$. $(K_\mathrm{sp}(\ce{Mg(OH)2}) = \pu{5.61E-12})$.
From $\mathrm{pH}$ I ...
1
vote
1
answer
70
views
An Index Poisoning Case Involving Dichlor and Carbonic Acid [closed]
I'm currently working an unusual case of poisoning, with Sodium Dichloro-S-Triazinetrione.
In my case, I need to know the expected reaction with carbonic acid.
I'm also curious if anyone could give ...
1
vote
1
answer
480
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 ...
2
votes
1
answer
318
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{...
9
votes
2
answers
959
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
vote
1
answer
366
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 $\...
-1
votes
1
answer
199
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 ...
0
votes
0
answers
66
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
0
answers
74
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 ...
1
vote
0
answers
101
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 ...
0
votes
0
answers
126
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 ...
0
votes
2
answers
1k
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 ...
0
votes
0
answers
550
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
1
answer
987
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^{-...
0
votes
1
answer
38
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. ...
1
vote
1
answer
967
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 ...
2
votes
2
answers
116
views
Criterion for gravimetric analysis of silver
If the only criterion for gravimetric analysis of silver is solubility of precipitate, which one of the following two compound are we supposed to choose? $K_\mathrm{s}(\ce{AgCl}) = \pu{1.78E-10}$ and ...
2
votes
0
answers
56
views
Calculating the solubility for chromium(III) hydroxide using the complex ion constant
Problem
$$
\begin{align}
\ce{Cr(OH)3(s) &<=> Cr^3+(aq) + 3 OH-(aq)} &\quad K_\mathrm{sp} &= \pu{6.7E-31} \\
\ce{Cr^3+(aq) + 4 OH-(aq) &<=> Cr(OH)4-(aq)} &\quad K_\...
1
vote
2
answers
1k
views
Does carbonation permanently increase the acidity of soda water?
If you carbonate water, and then expose the resulting soda water to the atmosphere and wait until it goes completely flat, will the (former) soda water end up more acidic in final equilibrium than ...
0
votes
0
answers
138
views
Problem in the calculation of ionic strength of a solution
Recently I've been trying to answer the question 10-13 (c) of 9th edition of Fundamentals of Analytical Chemistry of Skoog et al. Comparing my answers with the student manual , I realized that my ...
0
votes
1
answer
271
views
Why are some weak acid equilibrium approximations invalid in very dilute solutions?
Using two approximations for the dissociation of a weak acid, we can write
$$K_\mathrm{a}= \frac{[\ce{H+(aq)}]^2}{[\ce{HA(aq)}]}$$
One of these two approximations we use is that the concentration of ...
-3
votes
1
answer
5k
views
pKa = pH for strong acid — strong base?
I have learnt that for a weak acid — strong base titration, $\mathrm{p}K_\mathrm{a} = \mathrm{pH}$ at the half equivalence point.
However, the same conclusion is not drawn when discussing strong acid —...
5
votes
1
answer
403
views
Common Ion Effect - Ionic Equilibrium
Question
In which of the aqueous solutions of the following, dissociation of $\ce{NH4OH}$ will be minimum?
A) $\ce{NaOH}$
B) $\ce{H2O}$
C) $\ce{NH4Cl}$
D) $\ce{NaCl}$
My Thoughts
My book says that ...
0
votes
0
answers
115
views
Effect of adding an acid or base to water with respect to concentration of ions
So I know that there's auto-ionization of water according to:
$$\ce{2H2O <=> H3O+ +OH-} \tag{1}$$
If I have pure water where the concentrations of both $\ce{H3O+}$ and $\ce{OH-}$ is $10^{-7}$
...
-1
votes
1
answer
512
views
An equilibrium question involving mixing equal volumes of HCl and H2SO4
Question: Calculate the concentrations of H3O(+) and SO4(2-) in a solution prepared by mixing equal volumes of 0.2M HCl and 0.6M H2SO4. (Ka1 for H2SO4 is very large, and Ka2 for H2SO4 is 1.2E-2)
Here ...
0
votes
4
answers
572
views
How many grams of sodium phosphate must be added to precipitate as much of one ion as possible?
Problem text:
Solid sodium phosphate is slowly added to $\pu{200 mL}$ of a solution containing $\pu{0.002 mol}$ of aluminum chloride and $\pu{0.001 mol}$ of calcium chloride (assuming no volume ...
0
votes
2
answers
712
views
How to calculate mass of calcium fluoride that will dissolve in sodium fluoride solution?
The solubility product of calcium fluoride, $\ce{CaF2},$ is $\pu{1.46E-10 mol^3 dm^{-9}.}$
What mass of calcium fluoride will dissolve in $\pu{500 cm^3}$ of $\pu{0.10 mol dm^{-3}}$ sodium fluoride ...
2
votes
2
answers
2k
views
Equilibrium involving both gas phase and aqueous phase
If I have been given an equation that involves a gas-aqueous phase equilibria, how do I write the equilibrium constant?
I have come across several questions that give equations having BOTH gas and ...
-1
votes
1
answer
2k
views
How to calculate the amount of water required to increase the pH of a solution from 2.1 to 4? [closed]
After working out the problem with certain approximation of considering the initial pH=2, my answer came out to be around 1 litre of water. But the correct answer is 79 litres of water. Can anyone ...
1
vote
3
answers
314
views
How to decrease the percent of ammonia that is converted to the ammonium ion in water? [closed]
Ammonia is a weak base that reacts with water according to this equation:
NH3(aq) + H2O(l) ⇌ NH4+(aq) + OH −(aq)
Will Fe(NO3)3 decrease the ...
-1
votes
3
answers
1k
views
Are aqueous (aq) elements involved in equilibrium?
The reaction was something like this:
A (s) + B (l) yields to C (aq) + D (aq)
The question asked: If you added another D, which way would the equilibrium shift to?
I answered that it would have no ...