ElectrochemistryHard
Question
At 298K the standard free energy of formation of H2O(l) is -237.20 kJ/mole while ᐃGo of its ionisation into H+ ion and hydroxyl ions is 80 kJ/mole, then the emf of the following cell at 298 K will be
H2(g,1 bar) | H+ (1M) || OH- (1M) | O2 (g, 1bar)
H2(g,1 bar) | H+ (1M) || OH- (1M) | O2 (g, 1bar)
Options
A.0.40 V
B.0.81 V
C.1.23 V
D.-0.40 V
Solution
Cell reaction Cathode : H2O(l) + 
O2(g) + 2e- → 2OH-(aq.)
Anode : H2(g) → 2H+ (aq.) + 2e-
____________________________________
H2O(l) +
O2(g) + H2(g) → 2H+(aq.) + 2OH-(aq.)
Also we have
H2(g) +
O2(g) → H2O(l) ᐃGof = - 237.2 kJ/mole
H2O(l) → H+(aq.) + OH- (aq.) ᐃGo = 80 kJ/mole
Hence for cell reaction
ᐃGo = -77.20 kJ/mole So, Eo = -
= 0.40 V
O2(g) + 2e- → 2OH-(aq.)Anode : H2(g) → 2H+ (aq.) + 2e-
____________________________________
H2O(l) +
O2(g) + H2(g) → 2H+(aq.) + 2OH-(aq.)Also we have
H2(g) +
O2(g) → H2O(l) ᐃGof = - 237.2 kJ/moleH2O(l) → H+(aq.) + OH- (aq.) ᐃGo = 80 kJ/mole
Hence for cell reaction
ᐃGo = -77.20 kJ/mole So, Eo = -
= 0.40 VCreate a free account to view solution
View Solution FreeMore Electrochemistry Questions
When an electric current is passed through an aqueous solution of the following, the concentrations of cation as well as...An electrolytic cell contains a solution of Ag2SO4 and platinum electrodes. A current is passed until 1.6 g of O2 has be...The standard reduction potentials in acidic conditions are 0.77 V and 0.53 V, respectively, for Fe3+|Fe2+ and I3−|I− cou...How much the potential of a hydrogen electrode will change when its solution initially at pH = 0 is neutralised to pH = ...Which process occurs in the electrolysis of an aqueous solution of nickel chloride at nickel anode?...