All Questions
Tagged with equilibrium redox
33
questions
4
votes
2
answers
804
views
Acid dissociation constant from conductometric data
$\ce{0.007 M}$ aq. solution of anilinium hydrochloride had molar conductivity equal to $\pu{119.4 S cm2 mol-1}$, which became $\pu{103 S cm2 mol-1}$ when a few drops of aniline were added to the ...
- 828
-3
votes
1
answer
148
views
Side reaction of I− and acidity of HI
In acidic conditions, I− tends to get oxidised by atmospheric oxygen to give iodine. This is evident in iodine based titration, where upon leaving the setup, blue colour of starch reappears as iodine ...
- 155
1
vote
1
answer
768
views
Why is the theoretical value of the electrode potential different to the experimental value for Cu and Al for a galvanic cell by using Nernst equation
I've construct a galvanic cell with the Al strip putting in the Aluminum nitrate solution and Cu strip putting in the CuSO4 solution. KNO3 is used as the salt bridge in this experiment. The question ...
- 11
0
votes
0
answers
49
views
Concentration of solution when a battery reaches equilibrium
Problem: We want to build a battery employing as electrodes ${\text{PbSO}_4}_{(s)} | {\text{Pb}}_{(s)}\ (E^º=-0.351\ V)$ i ${\text{Cd}}_{(aq)}^{2+} | {\text{Cd}}_{(s)}\ (E^º=-0.4026\ V)$ in a solution ...
- 111
4
votes
1
answer
120
views
Redox titration, complex formation effect on lg'K?
We have performed the following redox titration
(1): $\ce{MnO_4^- + 8H^+ + 5Fe^2+ <=> Mn^2+ + 4H_2O + 5Fe^3+}$
where we have used a iron(II)solution (the analyte) and titrated it with a ...
- 43
-3
votes
1
answer
71
views
Voltaic cell equilibrium confusion
In a voltaic cell, taking one with $\ce{Zn}$ and $\ce{Cu }$ electrodes for an example, an EMF is formed because the equilibria at the $\ce{Zn}$ electrode is shifted more towards the $\ce{Zn^2+ + 2e-}$ ...
- 126
1
vote
2
answers
338
views
Effect of H+ concentration on equilibria
Considering the two equilibriums below, when the $[\ce{H+}]$ decreases, my book says that equilibrium \eqref{rxn:2} will shift to the left by a greater extent compared to equilibrium \eqref{rxn:1} ...
- 242
2
votes
0
answers
41
views
Do decomposition potentials change during electrolysis?
I was just wondering if decomposition potentials actually change during electrolysis. For example, if we reversed the Daniell cell reaction so that copper is oxidized, the half cell reactions would be:...
user115162
0
votes
1
answer
170
views
Calculating Gibbs free energy change when the state of ions is unknown
Problem
Calculate $\Delta G^\circ$ for the following reaction:
$$\ce{Zn(s) + Ag2O(s) + H2O(l) -> Zn^{+2}(aq) + 2Ag(s) + 2OH-(aq)}$$
Given $E^\circ_{\ce{Ag+/Ag}} = \pu{0.80 V}$, $E^\circ_{\ce{Zn^{+...
- 1,817
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
$$\boxed{E^\circ_\ce{Cl^-|Ag,AgCl} = E^\circ_\ce{Ag^+|Ag} + \frac{RT}{F}\ln K_\mathrm{...
- 750
1
vote
0
answers
702
views
Sodium hydroxide reaction with manganese dioxide [duplicate]
I came across a website that said it is possible for sodium hydroxide to react with manganese dioxide at temperatures near 0 degrees Celsius. The reaction goes:
2MnO2 + 3NaOH ⇄ MnO(OH) + Na3MnO4 + H2O
...
- 11
1
vote
1
answer
221
views
Why is "activity" of gaseous component equal to its partial pressure but that of aqueous component its concentration?
While solving an electrochemistry problem I had to calculate the reaction quotient of this reaction:
$$\ce{2Fe(s) + 4H+(aq) + O2(g) -> 2Fe^{2+} (aq) + 2H2O (l)}$$
It turns out to be: $$\ce{Q=\dfrac{...
- 750
1
vote
0
answers
174
views
Understanding Pourbaix diagram
I am recently taking courses in environmental chemistry and I was introduced to Pourbaix diagram. I was taught that the lines in the Pourbaix diagrams are equilibrium lines. Lets take as an example ...
- 766
2
votes
2
answers
2k
views
Origin of electrode potential and its connection with electric double layer
Recently, I was learning about electrode processes and I came across the topic of "electrode potentials".
I understood that at equilibrium, a potential difference was generated at the ...
- 221
1
vote
0
answers
141
views
What makes concentrated aqueous solutions of aluminium nitrate and aluminium chloride suitable to dissolve noble metals, specifically gold? [closed]
Aluminium nitrate is a strong oxidising agent and aluminium chloride acts as a Lewis acid. Also these solutions are claimed to have the abilities of aqua regia and therefore can dissolve noble metals.
...
- 11
10
votes
2
answers
4k
views
Why is chromate stable in basic medium and dichromate stable in acidic medium?
When I was studying the equilibrium existing between chromate and dichromate ions in the solution, I came to know that
Chromate ion is more stable in basic medium while dichromate ion is stable in ...
- 797
1
vote
0
answers
91
views
Equilibrium cell potential question
In an attempt to wrap my head around the basics of electrochemistry I'm working my way through Wesley R. Browne's 'Electrochemistry' primer.
With regards to the equilibrium potential of an ...
- 31
2
votes
3
answers
2k
views
Why is the voltage produced by a voltaic cell affected by temperature as described by the Nernst Equation?
I understand why changing the concentrations of the electrolytes in a voltaic cell affects the voltage. Given a zinc-copper cell for example, if I were to increase the concentration of the zinc ...
- 71
3
votes
1
answer
317
views
How can batteries reach equilibrium if the reactions are irreversible?
My book says that the batteries we have considered so far (Daniell cells) have a low life span because they reach equilibrium too quickly.
In the next paragraph, it states they are also made by ...
- 77
1
vote
1
answer
98
views
What would be the concentration of products in this calcium producing system?
I wanted to figure out a way to make calcium metal with potassium oxide. $\ce{K2O}$ undergoes disproportionation at $\pu{350-430 °C}:$
$$\ce{2 K2O -> K2O2 + 2 K}$$
Now, if I mixed in $\ce{CaO}$ (...
- 1,480
1
vote
1
answer
3k
views
Can an iodine clock reaction work without using a strong acid?
I'm going to do an iodine clock reaction for a project and we had to submit the materials and safety sheets for the experiment a while ago. I thought I could do one by using hydrogen peroxide, sodium ...
- 11
1
vote
0
answers
980
views
Manganese (II) oxidation by air
I am studying the reaction of dissolved dioxygen with manganese(II) hydroxide for the Winkler method:
2Mn(OH)2(s)+O2(aq)⟶2MnO2(s)+2H2O(l)
The ...
- 11
3
votes
1
answer
189
views
Are my intuitions about how batteries work right? [closed]
Being really fascinated by how electricity actually works, I started studying batteries.
I initilally understimated the complexity of this apparently-simple objects, and thorugh studies and researches ...
1
vote
2
answers
987
views
Calculate the cathode electrode potential in this redox reaction
In this problem I'm asked to calculate the electrode potential of the magnesium electrode ($E_{Mg^{2+}/Mg}$) given the red-ox reaction:$$\text{Mg(s)}+2\text{Ag}^+(10^{-2}\text{M})\leftrightarrow 2\...
-1
votes
1
answer
108
views
Redox - concentration cell
I'm studying galvanic cells and I've found a demonstration that lead me to an impossible result, so there must be a mistake, but I can't find what it is.
My problem is about concentration cells made ...
- 197
1
vote
2
answers
2k
views
Single electrode potential measurement
My textbook says that in a galvanic cell, it's not possible to measure single electrode potential independently. Instead, a Standard Hydrogen Electrode is used as the system is under equilibrium. Can ...
- 59
6
votes
2
answers
1k
views
Balancing complex haloform redox reaction
I just completed a haloform reaction experiment, using acetophenone and sodium hypochlorite to form benzoic acid and chloroform.
My lab report has a question regarding balancing the equation of the ...
- 61
23
votes
2
answers
5k
views
Why don't everyday things burn?
Ok, so I learned about the equilibrium constant. Now, I've seen that the equilibrium constant of burning is extremely small $(K \ll 1)$. here, I have a question. you see, $K$ is still NOT 0, which ...
- 411
2
votes
1
answer
4k
views
Does a Na2SO3 solution oxidize to Na2SO4 in an oxygen rich atmosphere?
Let's assume I have a pure solution of water and $\ce{NaOH}$. When this solution comes in contact with an atmoshpere containing inert gases and $\ce{SO2}$, then $\ce{NaHSO3}$ and $\ce{Na2SO3}$ will be ...
- 21
0
votes
1
answer
262
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How to calculate the concentration of lead(II) liberated from lead(IV) oxide under acidic conditions? [closed]
What is the concentration of $\ce{Pb^2+}$ in a lake that has a pH of $6.0$ and is in equilibrium with $\ce{PbO2(s)}$ and atmospheric oxygen?
\begin{align}
\ce{PbO2(s) + 4H+ + 2e- &-> Pb^2+ + ...
- 17