The document discusses the relationship between thermodynamic quantities such as Gibbs free energy (ΔG), equilibrium constant (Kc), cell potential (Ecell), and their significance. It provides equations relating these quantities and explains how ΔG and Kc can be used to predict the spontaneity and extent of chemical reactions. Examples are given to show how ΔG decreases as the reaction progresses towards equilibrium, and how the values of ΔG and Kc indicate the position of the reaction mixture between reactants and products.
Includes a discussion of Voltaic and electrolytic cells, the Nernst equation and the relationship between electrochemical processes, chemical equilibrium and free energy.
**More good stuff available at:
www.wsautter.com
and
http://www.youtube.com/results?search_query=wnsautter&aq=f
Includes a discussion of Voltaic and electrolytic cells, the Nernst equation and the relationship between electrochemical processes, chemical equilibrium and free energy.
**More good stuff available at:
www.wsautter.com
and
http://www.youtube.com/results?search_query=wnsautter&aq=f
CONDUCTIVITY-TYPES-VARIATION WITH DILUTION-KOHLRAUSCH LAW - TRANSFERENCE NUMBER -DETERMINATION - IONIC MOBILITY - APPLICATION OF CONDUCTANCE MEASUREMENTS - CONDUCTOMENTRIC TITRATION
This presentation consists of three topics that are:
1. conductance of electrolytic solution
2. Specific Conductance, Molar Conductance & Equivalent Conductance
3. Kohlrausch's Law
Electrochemistry,Electrolytic and Metallic Conduction,Specific Resistance or resistivity (ρ),Specific Conductance or Conductivity (κ),Equivalent Conductance (Λ), Molar Conductance (Λm),Variation of Conductance with Dilution,Debye-Hückel-Onsager Equation,Kohlransch’s Law of Independent Migration of Ions,Faraday’s Laws of Electrolysis,Electrochemical Cells,The Nernst Equation,Oxidation Number
Oxidation Number / State Method For Balancing Redox Reactions,Half-Reaction or Ion-Electron Method For Balancing Redox Reactions,Half-Reaction or Ion-Electron Method For Balancing Redox Reactions,Common Oxidising and Reducing Agents
CONDUCTIVITY-TYPES-VARIATION WITH DILUTION-KOHLRAUSCH LAW - TRANSFERENCE NUMBER -DETERMINATION - IONIC MOBILITY - APPLICATION OF CONDUCTANCE MEASUREMENTS - CONDUCTOMENTRIC TITRATION
This presentation consists of three topics that are:
1. conductance of electrolytic solution
2. Specific Conductance, Molar Conductance & Equivalent Conductance
3. Kohlrausch's Law
Electrochemistry,Electrolytic and Metallic Conduction,Specific Resistance or resistivity (ρ),Specific Conductance or Conductivity (κ),Equivalent Conductance (Λ), Molar Conductance (Λm),Variation of Conductance with Dilution,Debye-Hückel-Onsager Equation,Kohlransch’s Law of Independent Migration of Ions,Faraday’s Laws of Electrolysis,Electrochemical Cells,The Nernst Equation,Oxidation Number
Oxidation Number / State Method For Balancing Redox Reactions,Half-Reaction or Ion-Electron Method For Balancing Redox Reactions,Half-Reaction or Ion-Electron Method For Balancing Redox Reactions,Common Oxidising and Reducing Agents
Chemical equilibrium is briefly discussed with following topics:
Free energy change in a chemical reaction. Thermodynamic derivation of the law of chemical equilibrium.
Definition of ΔG and ΔG◦
Le Chatelier’s principle.
Relationships between Kp, Kc and Kx
Concept on Ellingham diagram & metallurgyArunesh Gupta
Ellingham Diagram decides the better reducing agent for metallurgy at different temperature, considering the Standard Free energy change of oxidation per mole of oxygen with temperature. It takes into consideration that for a reaction to be feasible, ∆rG < 0 or negative.
Introduction to AI for Nonprofits with Tapp NetworkTechSoup
Dive into the world of AI! Experts Jon Hill and Tareq Monaur will guide you through AI's role in enhancing nonprofit websites and basic marketing strategies, making it easy to understand and apply.
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
Synthetic Fiber Construction in lab .pptxPavel ( NSTU)
Synthetic fiber production is a fascinating and complex field that blends chemistry, engineering, and environmental science. By understanding these aspects, students can gain a comprehensive view of synthetic fiber production, its impact on society and the environment, and the potential for future innovations. Synthetic fibers play a crucial role in modern society, impacting various aspects of daily life, industry, and the environment. ynthetic fibers are integral to modern life, offering a range of benefits from cost-effectiveness and versatility to innovative applications and performance characteristics. While they pose environmental challenges, ongoing research and development aim to create more sustainable and eco-friendly alternatives. Understanding the importance of synthetic fibers helps in appreciating their role in the economy, industry, and daily life, while also emphasizing the need for sustainable practices and innovation.
The French Revolution, which began in 1789, was a period of radical social and political upheaval in France. It marked the decline of absolute monarchies, the rise of secular and democratic republics, and the eventual rise of Napoleon Bonaparte. This revolutionary period is crucial in understanding the transition from feudalism to modernity in Europe.
For more information, visit-www.vavaclasses.com
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
Palestine last event orientationfvgnh .pptxRaedMohamed3
An EFL lesson about the current events in Palestine. It is intended to be for intermediate students who wish to increase their listening skills through a short lesson in power point.
The Roman Empire A Historical Colossus.pdfkaushalkr1407
The Roman Empire, a vast and enduring power, stands as one of history's most remarkable civilizations, leaving an indelible imprint on the world. It emerged from the Roman Republic, transitioning into an imperial powerhouse under the leadership of Augustus Caesar in 27 BCE. This transformation marked the beginning of an era defined by unprecedented territorial expansion, architectural marvels, and profound cultural influence.
The empire's roots lie in the city of Rome, founded, according to legend, by Romulus in 753 BCE. Over centuries, Rome evolved from a small settlement to a formidable republic, characterized by a complex political system with elected officials and checks on power. However, internal strife, class conflicts, and military ambitions paved the way for the end of the Republic. Julius Caesar’s dictatorship and subsequent assassination in 44 BCE created a power vacuum, leading to a civil war. Octavian, later Augustus, emerged victorious, heralding the Roman Empire’s birth.
Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
The Roman Empire’s society was hierarchical, with a rigid class system. At the top were the patricians, wealthy elites who held significant political power. Below them were the plebeians, free citizens with limited political influence, and the vast numbers of slaves who formed the backbone of the economy. The family unit was central, governed by the paterfamilias, the male head who held absolute authority.
Culturally, the Romans were eclectic, absorbing and adapting elements from the civilizations they encountered, particularly the Greeks. Roman art, literature, and philosophy reflected this synthesis, creating a rich cultural tapestry. Latin, the Roman language, became the lingua franca of the Western world, influencing numerous modern languages.
Roman architecture and engineering achievements were monumental. They perfected the arch, vault, and dome, constructing enduring structures like the Colosseum, Pantheon, and aqueducts. These engineering marvels not only showcased Roman ingenuity but also served practical purposes, from public entertainment to water supply.
Biological screening of herbal drugs: Introduction and Need for
Phyto-Pharmacological Screening, New Strategies for evaluating
Natural Products, In vitro evaluation techniques for Antioxidants, Antimicrobial and Anticancer drugs. In vivo evaluation techniques
for Anti-inflammatory, Antiulcer, Anticancer, Wound healing, Antidiabetic, Hepatoprotective, Cardio protective, Diuretics and
Antifertility, Toxicity studies as per OECD guidelines
Model Attribute Check Company Auto PropertyCeline George
In Odoo, the multi-company feature allows you to manage multiple companies within a single Odoo database instance. Each company can have its own configurations while still sharing common resources such as products, customers, and suppliers.
IB Chemistry on Gibbs Free Energy, Equilibrium constant and Cell Potential
1. cellnFEG
Relationship between
Energetics and Equilibrium
cKRTG ln
STHG
Enthalpy
change
Entropy
change
Equilibrium
constant
Gibbs free
energy change
H
G
Relationshipbet ∆G, Kc and E cell
cellnFEG
STHG cKRTG ln
cK
Relationship between
Energetics and Cell Potential
G cellE
Gibbs free
energy change
Cell potential
F = Faraday constant
(96 500 Cmol-1)
n = number
electron
Relationship bet ∆G, Kc and Ecell
ΔGθ Kc Eθ/V Extent of rxn
> 0 < 1 < 0 No Reaction
Non spontaneous
ΔGθ = 0 Kc = 1 0 Equilibrium
Mix reactant/product
< 0 > 1 > 0 Reaction complete
Spontaneous
ΔGθ Kc Eq mixture
ΔGθ = + 200 9 x 10-36 Reactants
ΔGθ = + 10 2 x 1-2 Mixture
ΔGθ = 0 Kc = 1 Equilibrium
ΔGθ = - 10 5 x 101 Mixture
ΔGθ = - 200 1 x 1035 Products
Relationship bet ∆G and Kc
shift to left (reactant)
shift to right (products)
cellE
G
cK
K
nF
RT
E cell ln
2. Magnitudeof Kc
Extendof reaction
How far rxn shift to right or left?
Not how fast
cK
Positionof equilibrium
cK
Temp
dependent
Extend
of rxn
Not how fast
Shift to left/
favour reactant
Shift to right/
favour product
cK
Relationship between
Equilibrium and Energetics
cKRTG ln
STHG
Enthalpy
change
Entropy
change
Equilibrium
constant
Gibbs free energy change
H
G cK
G
Energetically
Thermodynamically
Favourable/feasible
ΔGθ ln K Kc Eq mixture
ΔGθ -ve
< 0
Positive
( + )
Kc > 1 Product
(Right)
ΔGθ +ve
> 0
Negative
( - )
Kc < 1 Reactant
(left)
ΔGθ = 0 0 Kc = 1 Equilibrium
Measure work
available from system
Sign predict
spontaneity of rxn
Negative (-ve)
spontaneous
Positive (+ve)
NOT
spontaneous
veG veG
NOT
favourable
Energetically
favourable
Product formation NO product
cKRTG ln
3. Magnitudeof Kc
Extendof reaction
How far rxn shift to right or left?
Not how fast
cK
Positionof equilibrium
cK
Temp
dependent
Extend
of rxn
Not how fast
Shift to left/
favour reactant
Shift to right/
favour product
cK
Relationship between
Equilibrium and Energetics
cKRTG ln
STHG
Enthalpy
change
Entropy
change
Equilibrium
constant
Gibbs free energy change
H
G cK
ΔGθ ln K Kc Eq mixture
ΔGθ -ve
< 0
Positive
( + )
Kc > 1 Product
(Right)
ΔGθ +ve
> 0
Negative
( - )
Kc < 1 Reactant
(left)
ΔGθ = 0 0 Kc = 1 Equilibrium
cKRTG ln
STHG
∆Hsys ∆Ssys ∆Gsys Description
- +
∆G = ∆H - T∆S
∆G = - ve
Spontaneous, All Temp
+ -
∆G = ∆H - T∆S
∆G = + ve
Non spontaneous, All Temp
+ +
∆G = ∆H - T∆S
∆G = - ve
Spontaneous, High ↑ Temp
- -
∆G = ∆H - T∆S
∆G = - ve
Spontaneous, Low ↓ Temp
Relationshipbet ∆G and Kc
4. G
Energetically
Thermodynamically
Favourable/feasible
Sign predict
spontaneity of rxn
veG veG
NOT
favourable
Energetically
favourable
Product formation NO product
KRTG ln
Predictwill rxn occur with ΔG and Kc
cK
Very SMALL
Kc < 1
Shift to right/
favour product
Shift to left/
favour reactant
Very BIG
Kc > 1
veG veG
KRTG ln
1cK 1cK
Negative (-ve)
spontaneous
Positive (+ve)
NOT
spontaneous
Relationship bet ∆G and Kc
ΔGθ Kc Eq mixture
ΔGθ = + 200 9 x 10-36 Reactant
ΔGθ = + 10 2 x 1-2 Mixture
ΔGθ = 0 Kc = 1 Equilibrium
ΔGθ = - 10 5 x 101 Mixture
ΔGθ = - 200 1 x 1035 Products
shift to left (reactant)
shift to right (product)
G, Gibbs free energy
A
Mixture composition
B
100% A 100% B
∆G decreases ↓
30 % A
70 % B
Equilibrium mixture
∆G < 0
∆G = 0 (Equilibrium)
↓
Free energy minimum
∆G < 0
∆G < 0
∆G = 0
Free energy system is lowered on the way to equilibrium
Rxn proceed to minimum free energy ∆G = 0
System seek lowest possible free energy
Product have lower free energy than reactant
∆G < 0 product
reactant
5. G
Energetically
Thermodynamically
Favourable/feasible
Sign predict
spontaneity of rxn
veG veG
NOT
favourable
Energetically
favourable
Product formation NO product
KRTG ln
cK
Very SMALL
Kc < 1
Shift to right/
favour product
Shift to left/
favour reactant
Very BIG
Kc > 1
veG veG
KRTG ln
1cK 1cK
Negative (-ve)
spontaneous
Positive (+ve)
NOT
spontaneous
Relationship bet ∆G, Q and Kc
G, Gibbs free energy
A
B
100% A 100% B
∆G decreases ↓
30 % A
70 % B
Equilibrium mixture
∆G < 0
∆G = 0 (Equilibrium)
↓
Free energy
minimum
∆G < 0
∆G < 0
∆G = 0
∆G < 0 product
reactant
G, Gibbs free energy
reactant product∆G < 0
A
B
∆G decreases ↓
100% A 100% B30 % A
70 % B
∆G = 0
Q = K
∆G < 0
Q < K
∆G > 0
∆G < 0
Q > K
∆G > 0
A ↔ B A ↔ B
Equilibrium mixture
Predictwill rxn occur with ΔG and Kc
6. Relationship bet ∆G and Kc
G, Gibbs free energy
A
B
100%
A
100%
B
∆G decreases ↓
30 % A
70 % B
Equilibrium mix close to product
∆G < 0
∆G = 0 (Equilibrium)
↓
Free energy minimum
∆G < 0
∆G < 0
∆G = 0
∆G < -10
Kc > 1
A ↔ B A ↔ B
G, Gibbs free energy
A
B
∆G decreases ↓
∆G < -100
100%
A
100%
B
∆G = 0 (Equilibrium)
↓
Free energy minimum
Kc > 1Equilibrium mix close to product
10 % A
90 % B
∆G < 0
∆G < 0 ∆G = 0
∆G very –ve → Kc > 1 → (more product/closeto completion)∆G –ve → Kc > 1 → (more product > reactant)
A ↔ B
G, Gibbs free energy
100%
A
100%
B
A
B
∆G +ve → Kc < 1 → (more reactant > product)
∆G > +10
∆G = 0 (Equilibrium)
↓
Free energy minimum
Kc < 1
∆G increases ↑
70 % A
30 % B
Equilibrium mix close to reactant
∆G < 0
∆G = 0
A ↔ B
G, Gibbs free energy
∆G more +ve → Kc < 1 → (All reactant / no product at all)
A
∆G = 0 (Equilibrium)
↓
Free energy minimum
Kc < 1100%
A
100%
B
Equilibrium mix close to reactant/ No reaction.
∆G > +100
B
90 % A
10 % B
∆G increases ↑
∆G = 0
∆G < 0
reactant
reactant
reactant
reactant
productproduct
product product
7. Relationship bet ∆G and Kc
shift to left (reactant)
shift to right (product)
G, Gibbs free energy
A
B
100%
A
100%
B
∆G decreases ↓
30 % A
70 % B
Equilibrium mixture
∆G < 0
∆G = 0 (Equilibrium)
↓
Free energy minimum
∆G < 0
∆G < 0
∆G = 0
Free energy system is lowered on the way to equilibrium
Rxn proceed to minimum free energy ∆G = 0
System seek lowest possible free energy
Product have lower free energy than reactant
∆G < -10
Kc > 1
A ↔ B A ↔ B
G, Gibbs free energy
A
B
∆G decreases ↓
∆G < -100
100%
A
100%
B
∆G = 0 (Equilibrium)
↓
Free energy minimum
Kc > 1Equilibrium mixture
10 % A
90 % B
∆G < 0
∆G < 0 ∆G = 0
∆G very –ve → Kc > 1 → (All product/closeto completion)∆G –ve → Kc > 1 → (more product > reactant)
∆G
∆G = 0
∆G > 0
∆G < 0
No reaction/most reactants
Kc <1
Complete rxn/Most products
Kc > 1
Kc = 1 (Equilibrium)
Reactants= Products
reactant
reactant
ΔGθ Kc Eq mixture
ΔGθ = + 200 9 x 10-36 Reactant
ΔGθ = + 10 2 x 1-2 Mixture
ΔGθ = 0 Kc = 1 Equilibrium
ΔGθ = - 10 5 x 101 Mixture
ΔGθ = - 200 1 x 1035 Products
8. 298314.8
)212000(
ln
RT
G
Kc
Zn ↔ Zn2+ + 2e Eθ = +0.76
Cu2+ + 2e ↔ Cu Eθ = +0.34
Zn + Cu2+ → Zn 2+ + Cu Eθ = +1.10V
Zn half cell (-ve)
Oxidation
Cu half cell (+ve)
Reduction
Anode Cathode
Zn(s) | Zn2+
(aq) || Cu2+
(aq) | Cu (s)
Cell diagram
Anode Cathode
Half Cell Half Cell
(Oxidation) (Reduction)
Salt Bridge Flow
electrons
Zn/Cu Voltaic Cell
-e -e
Zn/Cu half cells
Eθ
cell = Eθ
(cathode) – Eθ
(anode)
Eθ
cell = +0.34 – (-0.76) = +1.10V
Zn 2+ + 2e ↔ Zn (anode) Eθ = -0.76V
Cu2+ + 2e ↔ Cu (cathode) Eθ = +0.34V
Std electrode potential as std reduction potential
Find Eθ
cell (use reduction potential)Find Eθ
cell (use formula)
Eθ
cell = Eθ
(cathode) – Eθ
(anode)
Zn 2+ + 2e ↔ Zn Eθ = -0.76V
Cu2+ + 2e ↔ Cu Eθ = +0.34V
Oxidized sp ↔ Reduced sp Eθ/V
Li+ + e- ↔ Li -3.04
K+ + e- ↔ K -2.93
Ca2+ + 2e- ↔ Ca -2.87
Na+ + e- ↔ Na -2.71
Mg 2+ + 2e- ↔ Mg -2.37
Al3+ + 3e- ↔ AI -1.66
Mn2+ + 2e- ↔ Mn -1.19
H2O + e- ↔ 1/2H2 + OH- -0.83
Zn2+ + 2e- ↔ Zn - 0.76
Fe2+ + 2e- ↔ Fe -0.45
Ni2+ + 2e- ↔ Ni -0.26
Sn2+ + 2e- ↔ Sn -0.14
Pb2+ + 2e- ↔ Pb -0.13
H+ + e- ↔ 1/2H2 0.00
Cu2+ + e- ↔ Cu+ +0.15
SO4
2- + 4H+ + 2e- ↔ H2SO3 +0.17
Cu2+ + 2e- ↔ Cu + 0.34
1/2O2 + H2O +2e- ↔ 2OH- +0.40
+
+1.10 V
Eθ
Zn/Cu = 1.10V
Cu2+
-
-
-
-
Zn Cu
+
+
+
+
cellnFEG
E cell with ∆G
F = Faraday constant
(96 500 Cmol-1)
n = number electron
cellnFEG
kJJG
G
212212300
10.1965002
∆G –ve, E +ve, K > 1
∆G <0, E > 0, K > 1
↓
Rxn SpontaneouscKRTG ln
Equilibrium
constant
Gas constant, 8.314
∆G with Kc
cKRTG ln 37
103.1 cK
Favour products
9. Zn ↔ Zn2+ + 2e Eθ = +0.76
2Ag++2e ↔ 2Ag Eθ = +0.80
Zn + Ag+ → Zn 2+ + Ag Eθ = +1.56V
Zn half cell (-ve)
Oxidation
Ag half cell (+ve)
Reduction
Anode Cathode
Zn(s) | Zn2+
(aq) || Ag+
(aq) | Ag (s)
Cell diagram
Anode Cathode
Half Cell Half Cell
(Oxidation) (Reduction)
Salt Bridge Flow
electrons
Zn/Ag Voltaic Cell
-e -e
Zn/Ag half cells
Eθ
cell = Eθ
(cathode) – Eθ
(anode)
Eθ
cell = +0.80 – (-0.76) = +1.56V
Zn 2+ + 2e ↔ Zn (anode) Eθ = -0.76V
Ag + + e ↔ Ag(cathode) Eθ = +0.80V
Std electrode potential as std reduction potential
Find Eθ
cell (use reductionpotential)Find Eθ
cell (use formula)
Eθ
cell = Eθ
(cathode) – Eθ
(anode)
Zn 2+ + 2e ↔ Zn Eθ = -0.76V
Ag+ + e ↔ Ag Eθ = +0.80V
Oxidized sp ↔ Reduced sp Eθ/V
Li+ + e- ↔ Li -3.04
K+ + e- ↔ K -2.93
Ca2+ + 2e- ↔ Ca -2.87
Na+ + e- ↔ Na -2.71
Mg 2+ + 2e- ↔ Mg -2.37
Al3+ + 3e- ↔ AI -1.66
Mn2+ + 2e- ↔ Mn -1.19
H2O + e- ↔ 1/2H2 + OH- -0.83
Zn2+ + 2e- ↔ Zn - 0.76
Fe2+ + 2e- ↔ Fe -0.45
Ni2+ + 2e- ↔ Ni -0.26
Sn2+ + 2e- ↔ Sn -0.14
Pb2+ + 2e- ↔ Pb -0.13
H+ + e- ↔ 1/2H2 0.00
Cu2+ + e- ↔ Cu+ +0.15
SO4
2- + 4H+ + 2e- ↔ H2SO3 +0.17
Cu2+ + 2e- ↔ Cu +0.34
1/2O2 + H2O +2e- ↔ 2OH- +0.40
Cu+ + e- ↔ Cu +0.52
1/2I2 + e- ↔ I- +0.54
Fe3+ + e- ↔ Fe2+ +0.77
Ag+ + e- ↔ Ag + 0.80
1/2Br2 + e- ↔ Br- +1.07
+
+1.56 V
Ag
Eθ
Zn/Ag = +1.56V
Ag+
-
-
-
-
+
+
+
+
Zn
E cell with ∆G
cellnFEG
n = number electron F = Faraday constant
(96 500 Cmol-1)
cellnFEG
kJJG
G
301301000
56.1965002
∆G with Kc
cKRTG ln
Gas constant, 8.314 Equilibrium
constant
cKRTG ln
298314.8
)301000(
ln
RT
G
Kc
52
105.3 cK
∆G –ve, E +ve, K > 1
∆G <0, E > 0, K > 1
↓
Rxn Spontaneous
Favour products
10. Mn ↔ Mn2+ + 2e Eθ = +1.19
Ni2+ + 2e ↔ Ni Eθ = -0.26
Mn + Ni2+ → Mn2+ + Ni Eθ = +0.93V
Mn half cell (-ve)
Oxidation
Ni half cell (+ve)
Reduction
Anode Cathode
Mn(s) | Mn2+
(aq) || Ni2+
(aq) | Ni (s)
Cell diagram
Anode Cathode
Half Cell Half Cell
(Oxidation) (Reduction)
Salt Bridge Flow
electrons
Mn/Ni Voltaic Cell
-e -e
Mn/Ni half cells
Eθ
cell = Eθ
(cathode) – Eθ
(anode)
Eθ
cell = -0.26 – (-1.19) = +0.93V
Mn 2+ + 2e ↔ Mn (anode) Eθ = -1.19V
Ni2+ + 2e ↔ Ni (cathode) Eθ = -0.26V
Std electrode potential as std reduction potential
Find Eθ
cell (use reductionpotential)Find Eθ
cell (use formula)
Eθ
cell = Eθ
(cathode) – Eθ
(anode)
Mn 2+ + 2e ↔ Mn Eθ = -1.19V
Ni2+ + 2e ↔ Ni Eθ = -0.26V
Oxidized sp ↔ Reduced sp Eθ/V
Li+ + e- ↔ Li -3.04
K+ + e- ↔ K -2.93
Ca2+ + 2e- ↔ Ca -2.87
Na+ + e- ↔ Na -2.71
Mg 2+ + 2e- ↔ Mg -2.37
Al3+ + 3e- ↔ AI -1.66
Mn2+ + 2e- ↔ Mn -1.19
H2O + e- ↔ 1/2H2 -0.83
Zn2+ + 2e- ↔ Zn -0.76
Fe2+ + 2e- ↔ Fe -0.45
Ni2+ + 2e- ↔ Ni - 0.26
Sn2+ + 2e- ↔ Sn -0.14
Pb2+ + 2e- ↔ Pb -0.13
H+ + e- ↔ 1/2H2 0.00
Cu2+ + e- ↔ Cu+ +0.15
SO4
2- + 4H+ + 2e- ↔ H2SO3 + H2O +0.17
Cu2+ + 2e- ↔ Cu +0.34
1/2O2 + H2O +2e- ↔ 2OH- +0.40
Cu+ + e- ↔ Cu +0.52
1/2I2 + e- ↔ I- +0.54
+
+0.93 V
Eθ
Mn/Ni = +0.93V
Ni2+
-
-
-
-
NiMn
+
+
+
+Mn2+
E cell with ∆G
cellnFEG
n = number electron F = Faraday constant
(96 500 Cmol-1)
cellnFEG
kJJG
G
179179490
93.0965002
cKRTG ln
298314.8
)179000(
ln
RT
G
Kc
cKRTG ln
∆G with Kc
Gas constant, 8.314 Equilibrium
constant
∆G –ve, E +ve, K > 1
∆G <0, E > 0, K > 1
↓
Rxn Spontaneous
31
102.2 cK
Favour products
11. Oxidized sp ↔ Reduced sp Eθ/V
Li+ + e- ↔ Li -3.04
K+ + e- ↔ K -2.93
Ca2+ + 2e- ↔ Ca -2.87
Na+ + e- ↔ Na -2.71
Mg 2+ + 2e- ↔ Mg -2.37
Al3+ + 3e- ↔ AI -1.66
Mn2+ + 2e- ↔ Mn -1.19
H2O + e- ↔ H2 + OH- -0.83
Zn2+ + 2e- ↔ Zn -0.76
Fe2+ + 2e- ↔ Fe -0.45
Ni2+ + 2e- ↔ Ni -0.26
Sn2+ + 2e- ↔ Sn -0.14
H+ + e- ↔ H2 0.00
Cu2+ + e- ↔ Cu+ +0.15
SO4
2- + 4H+ + 2e- ↔ H2S +0.17
Cu2+ + 2e- ↔ Cu +0.34
Cu ↔ Cu2+ + 2e Eθ = -0.34
2H+ + 2e ↔ H2 Eθ = +0.00
Cu + 2H+→ Cu2+ +H2 Eθ = -0.34V
Rxn bet Cu + H+
Will it happen ?
Eθ
= -0.34V
(NON spontaneous)
О
Cu(s) | Cu2+
(aq) || H+ H2 | Pt (s)
(Oxidation) (Reduction)
Anode Cathode
Find Eθ
cell (use formula)
Eθ
cell = Eθ
(cathode) – Eθ
(anode)
Eθ
cell = 0.00 – (+0.34) = -0.34V
Eθ
= -0.34V
(NON spontaneous)
О
Rxn not feasible
Determinespontaneityrxn. Will it HAPPEN?
Find Eθ
cell (use reductionpotential)
Eθ
Cu/H+ = - 0.34V
E cell with ∆G
cellnFEG
n = number electron F = Faraday constant
(96 500 Cmol-1)
cellnFEG
kJJG
G
6565620
34.0965002
cKRTG ln
Gas constant, 8.314 Equilibrium
constant
∆G with Kc
cKRTG ln
298314.8
)65000(
ln
RT
G
Kc
∆G +ve, E -ve, K < 1
∆G >0, E < 0, K < 1
↓
Rxn Non Spontaneous
12
104
cK
Favour reactants
-0.34 V
acid
copper
Predictingwill rxn occur with ΔG, E cell and Kc
+
12. Oxidized sp ↔ Reduced sp Eθ/V
Li+ + e- ↔ Li -3.04
K+ + e- ↔ K -2.93
Ca2+ + 2e- ↔ Ca -2.87
Na+ + e- ↔ Na -2.71
Mg 2+ + 2e- ↔ Mg -2.37
Al3+ + 3e- ↔ AI -1.66
Mn2+ + 2e- ↔ Mn -1.19
H2O + e- ↔ H2 + OH- -0.83
Zn2+ + 2e- ↔ Zn -0.76
Fe2+ + 2e- ↔ Fe -0.45
Ni2+ + 2e- ↔ Ni -0.26
Sn2+ + 2e- ↔ Sn -0.14
H+ + e- ↔ H2 0.00
Cu2+ + e- ↔ Cu+ +0.15
SO4
2- + 4H+ + 2e- ↔ H2S +0.17
Cu2+ + 2e- ↔ Cu +0.34
Au3+ + 3e- ↔ Au +1.58
Rxn bet Au + H+
Will it happen ?
Eθ
= -1.58 V
(NON spontaneous)
О
Au(s) | Au3+
(aq) || H+ H2 | Pt (s)
(Oxidation) (Reduction)
Anode Cathode
Find Eθ
cell (use formula)
Eθ
cell = Eθ
(cathode) – Eθ
(anode)
Eθ
cell = 0.00 – (+1.58) = -1.58V
Eθ
= - 1.58 V
(NON spontaneous)
О
Rxn not feasible
Determinespontaneityrxn. Will it HAPPEN?
Find Eθ
cell (use reductionpotential)
Eθ
Au/H+ = - 1.58V
E cell with ∆G
cellnFEG
n = number electron F = Faraday constant
(96 500 Cmol-1)
cellnFEG
kJJG
G
914914820
58.1965006
cKRTG ln
Gas constant, 8.314 Equilibrium
constant
∆G with Kc
cKRTG ln
298314.8
)914000(
ln
RT
G
Kc
∆G +ve, E -ve, K < 1
∆G >0, E < 0, K < 1
↓
Rxn Non Spontaneous
50
104
cK
Kc too small – No reactionat all
-1.58 V
acid
gold
2Au ↔ 2Au3+ + 6e Eθ = -1.58
6H+ + 6e ↔ 3H2 Eθ = 0.00
2Au + 6H+ → 2Au3+ + 3H2 Eθ = -1.58V
+
Predictingwill rxn occur with ΔG, E cell and Kc
13. Eθ
= - 0.20 V
(NON spontaneous)
(Oxidation) (Reduction)
Anode Cathode
Find Eθ
cell (use formula)
Eθ
cell = Eθ
(cathode) – Eθ
(anode)
Eθ
cell = 0.34 – (0.54) = - 0.20V
Eθ
= - 0.20 V
(NON spontaneous)
Determinespontaneityrxn. Will it HAPPEN?
Find Eθ
cell (use reductionpotential)
Eθ
Cu2+/I- = - 0.20V
E cell with ∆G
cellnFEG
n = number electron F = Faraday constant
(96 500 Cmol-1)
cellnFEG
kJJG
G
3838600
20.0965002
cKRTG ln
Gas constant, 8.314 Equilibrium
constant
∆G with Kc
cKRTG ln
298314.8
)38000(
ln
RT
G
Kc
∆G +ve, E -ve, K < 1
∆G >0, E < 0, K < 1
↓
Rxn Non Spontaneous
7
102.2
cK
-1.58 V
Cu2+
I-Rxn bet Cu2+ +I-
Will it happen?
2I- ↔ I2 + 2e Eθ = -0.54
Cu2+ + 2e ↔ Cu Eθ = +0.34
2I- + Cu2+→ Cu + I2 Eθ = -0.20V
Pt(s) | I-, I2 || Cu2+
(aq) | Cu (s)
Favour reactants
Oxidized sp ↔ Reduced sp Eθ/V
Li+ + e- ↔ Li -3.04
K+ + e- ↔ K -2.93
Ca2+ + 2e- ↔ Ca -2.87
Na+ + e- ↔ Na -2.71
Mg 2+ + 2e- ↔ Mg -2.37
Al3+ + 3e- ↔ AI -1.66
Mn2+ + 2e- ↔ Mn -1.19
Zn2+ + 2e- ↔ Zn -0.76
Fe2+ + 2e- ↔ Fe -0.45
Ni2+ + 2e- ↔ Ni -0.26
Sn2+ + 2e- ↔ Sn -0.14
H+ + e- ↔ 1/2H2 0.00
Cu2+ + e- ↔ Cu+ +0.15
Cu2+ + 2e- ↔ Cu +0.34
1/2O2 + H2O +2e- ↔ 2OH- +0.40
Cu+ + e- ↔ Cu +0.52
I2 + 2e- ↔ I- +0.54
Rxn not feasible
О
О
- 0.20 V
Will I- oxidize
Cu2+ to Cu
Predictingwill rxn occur with ΔG, E cell and Kc
14. Click here to view free energy
PredictingSpontaneity of Rxn
Thermodynamic,ΔG Equilibrium, Kc
1cK
1cK
KRTG ln
G
veG
cK
1cK
Energetically
favourable
0G
Predictingrxn will occur?
N2(g) + 3H2(g) ↔ 2NH3(g)
H2O(l) ↔ H+
(aq)+ OH-
(aq)
Shift toward
reactants
Energetically
unfavourable
Non spontaneous
Mixture
reactant/productEquilibrium
veG Spontaneous Shift toward
product
79G
33G
6
10G
14
101
cK
5
105cK
Fe(s) + 3O2(g) ↔ 2Fe2O3(s) 261
101cK
Shift toward
reactants
Energetically
unfavourable
Shift toward
product
Energetically
favourable
Energetically
favourable
Kinetically unfavourable/(stable)
Rate too slow due to HIGH activation energy
Rusting Process
Energy barrier
Shift toward
product
Click here for notes
cellnFEG
Cell Potential
cellE
0cellE
0cellE
0cellE
0cellE
0cellE
0cellE
15. Eθ
= +0.44V
IB Questions
Esterification produce ethyl ethanoate. ΔG = -4.38kJmol-1 Cal Kc
CH3COOH(l) + C2H5OH(l) ↔ CH3COOC2H5(l) + H2O(l)
Kc = 5.9
cKRTG ln
RT
G
Kc
ln
29831.8
4380
ln
cK
2
?cK
NO oxidized to NO2. Kc = 1.7 x 1012. Cal ∆G at 298K1
3 4
2NO+ O2 ↔ NO2 ?G
cKRTG ln
11
12
7.6969772
)107.1ln(298314.8
kJmolJmolG
G
Predict if iron react with HCI in absence air. Cal E cell , ∆G and Kc
Oxidized sp ↔ Reduced sp Eθ/V
Fe2+ + 2e- ↔ Fe -0.44
2H+ + 2e- ↔ H2 0.00
O2 +2H2O+4e ↔ 4OH- +0.40
Fe2+ + 2e- ↔ Fe -0.44
2H+ + 2e- ↔ H2 0.00
О
О
Fe ↔ Fe2+ + 2e Eθ = +0.44
2H+ + 2e ↔ H2 Eθ = 0.00V
Fe + 2H+ → Fe2+ + H2 Eθ = +0.44V
cellnFEG
kJJG
G
8584900
44.0965002
cKRTG ln
298314.8
)85000(
ln
RT
G
Kc
14
108.7 cK
∆G –ve, E +ve, K > 1
∆G <0, E > 0, K > 1
↓
Rxn Spontaneous
Fe2+ + 2e- ↔ Fe -0.44
O2 +2H2O+4e ↔ 4OH- +0.40
2Fe ↔ 2Fe2+ + 4e Eθ = +0.44
O2+2H2O+4e↔ 4OH- Eθ = +0.40
2Fe+O2 +2H2O→2Fe2++4OH- Eθ = +0.84V
Eθ
= +0.84V
Oxidized sp ↔ Reduced sp Eθ/V
Fe2+ + 2e- ↔ Fe -0.44
2H+ + 2e- ↔ H2 0.00
O2 +2H2O+4e ↔ 4OH- +0.40
Predict iron react HCI in presence of air. Cal E cell , ∆G and Kc
О
О
cellnFEG
kJJG
G
324324000
84.0965004
cKRTG ln
298314.8
)324000(
ln
RT
G
Kc
56
108.2 cK
∆G –ve, E +ve, K > 1
∆G <0, E > 0, K > 1
↓
Rxn SpontaneousRusting is spontaneous
x 2
О
О
О
О
16. Predict if manganate will oxidize chloride ion?
MnO2 + 4H+ + 2CI- → Mn2+ + 2H2O + CI2
5
MnO2 +4H+ + 2e- ↔ Mn2+ + 2H2O +1.23
1/2CI2 + e- ↔ CI- +1.36
2CI- ↔ CI2 + 2e Eθ = -1.36
MnO2 + 4H+ + 2e ↔ Mn2+ + 2H2O Eθ = +1.23
MnO2 + 4H++2CI- → Mn2++2H2O+CI2 Eθ= -0.13V
Eθ
= -0.13V
Oxidized sp ↔ Reduced sp Eθ/V
Cr2O7
2-+ 14H+ + 6e- ↔ 2Cr3+ + 7H2O +1.33
MnO2 +4H+ + 2e- ↔ Mn2+ + 2H2O +1.23
1/2CI2 + e- ↔ CI- +1.36
MnO4
-
+ 8H+ + 5e- ↔ Mn2+ + 4H2O +1.51
Predict if MnO4
- able to oxidize aq CI- to CI2
2MnO4 + 16H+ + 10CI- → 2Mn2++ 8H2O + 5CI2
О
О
Oxidized sp ↔ Reduced sp Eθ/V
Cr2O7
2-+ 14H+ + 6e- ↔ 2Cr3+ + 7H2O +1.33
MnO2 +4H+ + 2e- ↔ Mn2+ + 2H2O +1.23
1/2CI2 + e- ↔ CI- +1.36
MnO4
-
+ 8H+ + 5e- ↔ Mn2+ + 4H2O +1.51
О
О
2CI- ↔ CI2 + 2e Eθ = -1.36
MnO4
- + 8H+ + 5e ↔ Mn2+ + 4H2O Eθ = +1.51
2MnO4 + 16H++10CI- → 2Mn2++8H2O+5CI2 Eθ= +0.15V
1/2CI2 + e- ↔ CI- +1.36
MnO4
-
+ 8H+ + 5e- ↔ Mn2+ + 4H2O +1.51
Eθ
= +0.15V
IB Questions
cellnFEG
kJJG
G
2525000
13.0965002
cKRTG ln
298314.8
)25000(
ln
RT
G
Kc
5
105.4
cK
∆G +ve, E -ve, K < 1
∆G >0, E < 0, K < 1
↓
Rxn Non Spontaneous
6
cellnFEG
kJJG
G
144144750
15.09650010
cKRTG ln
298314.8
)144000(
ln
RT
G
Kc
25
105.1 cK
∆G –ve, E +ve, K > 1
∆G <0, E > 0, K > 1
↓
Rxn Spontaneous
x 5
x 2
О
О
О
О