Q1 During electrolysisof aqueous solution of a salt pH in the space near one of the electrodes is increased - Chemistry - Electrochemistry

Question

Q1 During electrolysisof aqueous solution of a salt pH in the
space near one of the electrodes is increased Which of the
following salt solution was electrolyzed?
(1) KCL(2) CuCl2 (3) Cu(NO3)2 (4)
CuSO4
​
Q2 The ionic mbilityof alkali metal ions in aqueous solution is
maximum for
(1) Na+ (2) K+ (3) Rb+​ (4)
Li+

Q3 During the recharging of lead acid storage cell the reaction at
anode is
(1) Pb​2+ coverts toPb
(2)Pb​2+coverts toPb​4+
(3)Pbcoverts toPb​2+(4) Pb​4+
converts to Pb2+

Q4 Standard cell voltage for cell
Pb/Pb2+||Sn2+/Snis -0 01V If the cell is to
exhibit Ecell=0, the value of
log[Sn2+]/[Pb2 +] should be
(1) 0 33 (2) 0 5 (3) 1 5 (4) -0 5

Q5 The hydrogen electrode is dipped in a solution of pH = 3 at
25oC The reduction potential of the electrode would
be
(1) 0 177V (2) 0 087V (3) -0 177V (4) 0 059V

Q6 What would be the emf of the given cell?
Pt | H2(P1) | H+ (aq) | H2
(P2) |Pt​
(1) RT/ F ln P1 / P2(2)RT/ 2FlnP1/
P2 (3)RT/ FlnP2/ P1(4)RT/ 2FlnP2/
P1

Geetha · Accepted Answer

a
 KCl As the cation (K+) has lower electrode potential than H, hydrogen is liberated at the cathode
There is accululation of H+ at one electroded, resulting in increase in pHb
 Rb+
 The hydration enthalpy is in the orderLi+ > Na+ > K+ > Rb+ > Cs+As the hydration of Li+ is more, the hydrated ion atomic size is more for Li+ and less for Rb+so the mobility is faster for Rb+ and less for Li+c
 Pb2+ is converted to Pb
The overall cell reaction during recharge is2PbSO4 + 2 H2O →Pb + PbO2 + 2H2SO4d
 The cell reaction isAt anode : Pb →Pb2+ + 2e-At cathode : Sn2+ + 2e- → SnThe overall reaction isPb + Sn2+→Pb2+ + Snaccording to Nernst equationE = E0 -0
0591n log Pb2+Sn2+0 = -0 01 -0
05912 log Pb2+Sn2+0 = -0 01 +0
05912 log Sn2+Pb2+0
05912 log Sn2+Pb2+ = 0
01 log Sn2+Pb2+ = 0 01 ×20
0591 = 0 3384 e  E = -0
05911 × pH = -0
05911 × 3 = -0 177 Vf
 Option b is correct2H+ + 2e- →H2 (P2)H2 (P1) → 2H+ + 2e-overall cell reaction isH2(P1) →H2(P2)E = E0 - RT2F log P2P1 = 0 -RT2F log P2P1  =RT2F log P1P2