All Questions
Tagged with free-energy electrochemistry
24
questions
0
votes
0
answers
51
views
Change in Gibbs energy for lithium redox reaction
I was reading an electrochemistry book by Thomas F. Fuller, in this book the thermodynamic values for the lithium redox reaction at standard conditions are the following:
Reaction
$\Delta G^o$ [kJ/...
- 267
0
votes
1
answer
126
views
How does cell potential change with temperature for positive enthalpy and negative entropy?
A recent United States National Chemistry Olympiad question asked:
A certain voltaic cell has a standard cell potential that increases with increasing temperature. Which best explains this ...
- 206
-2
votes
1
answer
124
views
Inconsistency in between Nernst Equation and Gibbs Free Energy Equation [closed]
Part 1 - Derivation of the Gibbs Free Energy Equation: [copied from this]
Using the fundamental equations for the state function (and its natural variables):
\begin{align}
\mathrm{d}G &= -S\...
0
votes
1
answer
115
views
What is the difference between standard Gibbs energy and Gibbs energy of formation?
Good day guys,
I am reading a book on electrochemical engineering, I came across some definitions of Gibbs energy and I am a bit confused as the book does not go into a lot of detail.
The book first ...
- 267
0
votes
0
answers
18
views
Is the maximum work done by voltaic cell per mole of reaction? [duplicate]
From the equation $w_{elec,rev}=-nF\Delta E$, and n = the number of moles of electrons transferred in the overall redox reaction, does that make the work per mole of the redox reaction? I am confused ...
2
votes
0
answers
197
views
Gibbs energy of electron transfer
The reaction Gibbs free energy of a cell is
$\Delta_\mathrm{r}G^\circ = -nFE^\circ, \tag{1}$
and the Gibbs energy of photoinduced electron transfer according to IUPAC is
$$\Delta_\mathrm{ET}G^\circ = ...
user78790
0
votes
0
answers
34
views
How to use anodic and cathodic overpotentials to calculate electrolytic energy efficiency?
I am trying to calculate the energy efficiency for $\ce{CO2}$ reduction to formate, coupled to water oxidation based on literature data.
$$\ce{CO2 + 2e- + 2H+ -> HCOOH}$$
$$\ce{H2O -> 2H+ + 1/...
- 337
3
votes
1
answer
181
views
Derivation and visualization of cell potential dependency on temperature and entropy
Working from the thermodynamic identity
$$\Delta{S} = -\left(\frac{\partial{\Delta{G}}}{\partial{T}}\right)_p,$$
is it allowed to integrate both sides to obtain an expression derived from the Nernst ...
user85551
1
vote
2
answers
134
views
How does work from other sources affect Gibbs free energy of the system?
In most physical chemistry textbooks, Gibbs free energy is given like this:
$$\Delta_\mathrm rG = \Delta_\mathrm rG^\circ + RT\ln Q\tag{1}$$
and Gibbs free energy is part of this three-way ...
- 323
2
votes
1
answer
179
views
Expression for Gibb's free energy change for a cell reaction
According to Chemistry Libretexts, the Gibbs free energy change of a cell reaction is related to the cell voltage as
$$ \Delta G = -nFE,$$
where $n$ is the number of moles of electrons passed and $F$ ...
- 431
0
votes
3
answers
757
views
Why is this reaction spontaneous in standard conditions?
To study if this reaction is spontaneous I proceed in this way:
$$\ce{2H_{3}O^{+} +Fe ->H_{2} +Fe^{2+} + 2H_{2}O}$$
First I write the two semireaction:
$$reduction: \ \ \ce{2H_{3}O^{+} +2e^{-} ->...
- 193
4
votes
0
answers
81
views
Calculating ideal chemical work using extent of reaction and chemical potential [closed]
I have a electrochemical reactor assumed isothermal and isobaric with 4 reactions and I am trying to calculate the "ideal chemical work' exerted by each reaction using the extent of reactions for each ...
- 49
2
votes
2
answers
219
views
Where does Free Energy go in a Redox Reaction?
This doubt came to my mind while answering the following question:
Why does a voltaic cell not operate unless the two separate compartments are connected by an external circuit?
The answer seems ...
4
votes
2
answers
458
views
How come ∆G ≤ 0 is used for spontaneity in electrochemistry, not ∆G ≤ W(other)?
The spontaneity condition for a system at constant temperature and pressure in which the only type of work accomplished is of the $pV$ type can be expressed as:
$$\Delta G\le0\tag1$$
In case of ...
- 41
1
vote
0
answers
39
views
Relationship between Yield and Applied Potentials
This question revolves around this question from Atkins' Chemical Principles 5th ed., Chapter 13, Question 13.116:
Consider the electroplating of a metal $+1$ cation from a solution of unknown ...
- 1,441