1) Choose all of the statements from below which correctly describe issues perta
ID: 937244 • Letter: 1
Question
1) Choose all of the statements from below which correctly describe issues pertaining to the relationship between the emf of a reaction and its Gibbs free energy change.
a) The Gibbs free energy change and emf values of a reaction have opposite algebraic signs (+ vs. -).
b) Electron stoichiometry need not be used to interconvert a Gibbs free energy change and a reaction emf.
c) A mole of particles is more particles than a coulomb of particles.
d) Faraday's constant is not used to interconvert a Gibbs free energy change and a reaction emf.
e) A Gibbs free energy change involves coulombs of substances whereas an emf involves moles of electrons.
2) Calculate the standard Gibbs free energy changes at 25 oC for each of the reactions shown below using the Eo values given. Select whether each of these reactions is nonspontaneous, at equilibrium, or spontaneous under standard conditions.
(a) 1 Pb2+(aq) + 1 Mn(s) 1 Pb(s) + 1 Mn2+(aq) Eo = 1.054 VExplanation / Answer
1. a) The Gibbs free energy change and emf values of a reaction have opposite algebraic signs (+ vs. -). TRUE.
Reason : the formula says delta G = -nFEocell , so these two quantities G and E have opposite signs.
b) Electron stoichiometry need not be used to interconvert a Gibbs free energy change and a reaction emf. FALSE
Reason : the formula says delta G = -nFEocell , where n = no. of electrons transferred. So, electron stoichiometry is to be considered.
c) A mole of particles is more particles than a coulomb of particles. TRUE
Reason : 1 moles of particle = 6.022E 23 whereas 1 coulomb = 6.24E18
d) Faraday's constant is not used to interconvert a Gibbs free energy change and a reaction emf. FALSE
Reason : the formula says delta G = -nFEocell , where F= faraday's constant, so the given statement is false.
e) A Gibbs free energy change involves coulombs of substances whereas an emf involves moles of electrons. FALSE
Reason: A Gibbs free energy change involves moles of substances whereas an emf involves coulomb/charge of electrons.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.