Electrochemistry

What is a Battery?

-atom B wants an electron more than atom A (i.e. B is more electronegative than A)

-attach a wire to permit the conduction of electrons from A to B

-place in a salt bridge (e.g. electrolytic solution) to balance the charges of the resultant products so that the reaction can proceed without impedence

 

-Cathode is reduction (Cathy is fat, she eats electrons)

-Anode is oxidation (Anne is anorexic, she vomits electrons)

-electrons flow from anode to cathode

 

Introduction to Electrochemistry

 

Galvanic Cells (Voltaic Cells)

 

 

Electrolysis

 

3 、 31

 

-In electrolysis, the positive side of the battery pulls electrons from the anode

-In electrolysis, the negative side of the battery pushes electrons onto the cathode

-electrolysis uses a battery to force a redox reaction that is nonspontaneous (to force electrons onto the negative side)

 

 

zinc ions 
zinc 
electrode 
Zn 
zinc 
sulfate 
Anode 
(oxidation) 
zn (s) zn2+ (aq) + 2e- 
cu2+ (aq) + 2e- cu (s) 
Galvanic (Voltaic) Cell 
electrons 
salt bridge 
EO = -0.76 
EO - -0.34 
E cell = EO 
sulfate ions 
cu 
Direction of electron flow 
Anode (oxidation) 
copper 
electrode 
copper (Il) 
Electrolytic Cell 
Voltage Source 
Electrolyte 
such as NaCl 
Cathode (reduction) 
sulfate 
Cathode 
(reduction) 
2Cl- C12(g) + 2e- 
2Na+ + 2e- 2Na (D 
EO = 1.36V 
EO = -2.71V 
cathode 
- 0.34 v- (-0.76 V) = 1.10 v 
anode ¯ 
> O and AGO = -nFE, AGO for 
cell ¯ 
cathode 
- -2.71V - (1.36V) = -4.07V 
anode ¯ 
Given that EO 
galvanic 
Given that EO 
electrolytic 
< O and AG 
o = -nFE, AGO for an 
a galvanic cell must be negative and spontaneous! 
electrolytic ce// must be positive and nonspontaneous! 
Jack Westin

 

-Reduction ALWAYS occurs at the Cathode

-Oxidation ALWAYS occurs at the Anode

-electrons ALWAYS flow from anode to cathode

-only the charge of the cathode/anode changes from galvanic to electrolytic

 

Galvanic Cell Vs Electrolytic Cell differences

 

: -In this cell, Chemical 
energy is converted to 
electrical energy. 
2 • Anode e 
Cathode 
Electrical energy 
from an external 
Source is used to 
bring Chemical 
changes 
Anode 
Cathode

 

What is the standard potential of the half reaction: 1/2 O2(l) + 2H+ + 2e-  → H2O(l)? - Quora

-Eo is proportional to “electronegativity”; high Eo atoms want electrons the most (think E = electron wanting)

 

 

Electroplating

 

 

Electroplating Part 2

 

 

-in electroplating, the oxidation and reduction equations are for the same element

 

Electrolysis & Electroplating Practice Problems – Electrochemistry

 

Electroplating Problems 
X

 

 

qcqgsc

 

Standard Reduction Potentials of Half Reactions – Electrochemistry

 

Reduction Potentials 
cıa 4 a 
- acı- 
0.39

 

Cell Potential Problems – Electrochemistry

 

Cell Potential Problems 
0

 

Concentration Cells & Cell Potential Calculations – Electrochemistry

 

Concentration Cells 
A no 
tell 
—D.osql

 

ε- Ο 059) IOJQ

 

Cell Potential & Gibbs Free Energy, Standard Reduction Potentials, Electrochemistry Problems

 

sqq!9 9 ID!4.12Pd 1129

 

Equilibrium Constant K & Cell Potential Problems With Ksp – Electrochemistry

 

= 03

 

=3 
(기 
보/亐v- 
上뉞/43 표`] 
: 9 V 
-0ⅴ 
비 기- =

 

Nernst Equation Explained, Electrochemistry, Example Problems, pH, Chemistry, Galvanic Cell

 

Nernst Equation

 

。 フ 十 》 コ の く 広 
E ビ 切 円 
0

 

ε- Ο 059) IOJQ

-increasing the concentration of products decreases the cell potential (voltage)

 

Analagous to this equation:

 

 

 

 

 

Rechargeable Batteries:

 

Lead-acid Battery

 

 

Pb 
p b2 
H20 
Pb 
04 
2.1V 
Pb02 
2+ 
HSo-4 
H20 
PbS04

 

-the electrons given up by lead in the anode are taken up by the oxygen in PbO2, leaving a Pb2+ ion. Therefore, both sides result in a Pb2+ ion

 

Lead Acid Battery: How Do They Work? | Working Animation | Electrical4U

 

Lead Acid 
Battery: 
How Do They 
Work?

 

Trick to remember Reactions in Lead storage battery|ASN CHEMISTRY

 

04

 

Lead storage battery | Redox reactions and electrochemistry | Chemistry | Khan Academy

 

OX

 

Nickle-cadmium Batteries

 

https://www.youtube.com/watch?v=si7PaXtJX3k&ab_channel=SP