
Concept explainers
a)
Interpretation:
Half reactions; the anode and cathode have to be labelled.
Concept introduction:
Standard reduction potential: The voltage associated with a reduction reaction at an electrode when all solutes are 1M and all gases are at 1 atm. The hydrogen electrode is called the standard hydrogen electrode (SHE).
Standard emf:
Where both
The change in free-energy represents the maximum amount of useful work that can be obtained in a reaction:
Relation between
Relation between
Effect of concentration on cell Emf:
The mathematical relationship between the emf of galvanic cell and the concentration of reactants and products in a redox reaction under nonstandard-state conditions is,
As known
Dividing by –nF, the above equation becomes,
Nernst equation: The Nernst equation is used to calculate the cell voltage under nonstandard-state conditions.
a)

Explanation of Solution
Figure.1
For the given redox reactions,
In the galvanic cell, Oxidation occurs at anode and reduction occurs at cathode.
Therefore,
Anode (Oxidation):
Cathode (Reduction):
b)
Interpretation:
The minimum voltage needed to drive the reaction has to be calculated.
Concept introduction:
Standard reduction potential: The voltage associated with a reduction reaction at an electrode when all solutes are 1M and all gases are at 1 atm. The hydrogen electrode is called the standard hydrogen electrode (SHE).
Standard emf:
Where both
b)

Explanation of Solution
The emf values for the two given half-reactions are,
Anode (Oxidation):
Cathode (Reduction):
Calculated standard emf for galvanic cell as follows,
The minimum voltage needed to drive the reaction is
c)
Interpretation:
The emf of a given galvanic cell has to be calculated.
Concept introduction:
Standard reduction potential: The voltage associated with a reduction reaction at an electrode when all solutes are 1M and all gases are at 1 atm. The hydrogen electrode is called the standard hydrogen electrode (SHE).
Standard emf:
Where both
Effect of concentration on cell Emf:
The mathematical relationship between the emf of galvanic cell and the concentration of reactants and products in a
As known
Dividing by –nF, the above equation becomes,
Nernst equation: The Nernst equation is used to calculate the cell voltage under nonstandard-state conditions.
c)

Explanation of Solution
Given: Current= 10.0 A; Time,
Convert Current into coulomb:
As known,
Convert number of Coulombs into mole of electrons:
Convert mole of electrons into number of moles:
1 mole of Cobalt
‘X’of Cobalt =
Therefore, no.of moles of Cobalt is
Assuming solution volumes of 1.00L, the concentration of Co2+ in solution after 2hours is 2.373 M, and the concentration of Mg2+ in solution after 2 hours is 1.627 M. we use the Nernst equation to solve for
Calculation of non-standard emf value using Nernst equation:
The reaction quotient for the given reaction is,
The concentration of pure solids and pure liquids do not appear in the expression for Q.
Hence, the reaction quotient becomes,
Substitute known constant values of R, T and F into Nernst equation becomes as follows,
The number of electrons transferred in the given redox reaction is TWO (n=2) and
The emf of the given cell reaction is
Want to see more full solutions like this?
Chapter 19 Solutions
EBK GENERAL CHEMISTRY: THE ESSENTIAL CO
- H-Br Energy 1) Draw the step-by-step mechanism by which 3-methylbut-1-ene is converted into 2-bromo-2-methylbutane. 2) Sketch a reaction coordinate diagram that shows how the internal energy (Y- axis) of the reacting species change from reactants to intermediate(s) to product. Brarrow_forward2. Draw the missing structure(s) in each of the following reactions. The missing structure(s) can be a starting material or the major reaction product(s). C5H10 H-CI CH2Cl2 CIarrow_forwardDraw the products of the stronger acid protonating the other reactant. དའི་སྐད”“ H3C OH H3C CH CH3 KEq Product acid Product basearrow_forward
- Draw the products of the stronger acid protonating the other reactant. H3C NH2 NH2 KEq H3C-CH₂ 1. Product acid Product basearrow_forwardWhat alkene or alkyne yields the following products after oxidative cleavage with ozone? Click the "draw structure" button to launch the drawing utility. draw structure ... andarrow_forwardDraw the products of the stronger acid protonating the other reactant. H3C-C=C-4 NH2 KEq CH H3C `CH3 Product acid Product basearrow_forward
- 2. Draw the missing structure(s) in each of the following reactions. The missing structure(s) can be a starting material or the major reaction product(s). C5H10 Br H-Br CH2Cl2 + enant.arrow_forwardDraw the products of the stronger acid protonating the other reactant. KEq H₂C-O-H H3C OH Product acid Product basearrow_forwardDraw the products of the stronger acid protonating the other reactant. OH KEq CH H3C H3C `CH3 Product acid Product basearrow_forward
- 2. Draw the missing structure(s) in each of the following reactions. The missing structure(s) can be a starting material or the major reaction product(s). Ph H-I CH2Cl2arrow_forward3 attempts left Check my work Draw the products formed in the following oxidative cleavage. [1] 03 [2] H₂O draw structure ... lower mass product draw structure ... higher mass productarrow_forward2. Draw the missing structure(s) in each of the following reactions. The missing structure(s) can be a starting material or the major reaction product(s). H-Br CH2Cl2arrow_forward
- ChemistryChemistryISBN:9781305957404Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCostePublisher:Cengage LearningChemistryChemistryISBN:9781259911156Author:Raymond Chang Dr., Jason Overby ProfessorPublisher:McGraw-Hill EducationPrinciples of Instrumental AnalysisChemistryISBN:9781305577213Author:Douglas A. Skoog, F. James Holler, Stanley R. CrouchPublisher:Cengage Learning
- Organic ChemistryChemistryISBN:9780078021558Author:Janice Gorzynski Smith Dr.Publisher:McGraw-Hill EducationChemistry: Principles and ReactionsChemistryISBN:9781305079373Author:William L. Masterton, Cecile N. HurleyPublisher:Cengage LearningElementary Principles of Chemical Processes, Bind...ChemistryISBN:9781118431221Author:Richard M. Felder, Ronald W. Rousseau, Lisa G. BullardPublisher:WILEY





