CHEMISTRY By Kalpit Sir
(iv) How will concentration of Zn2+ and Ag+ ions be affected when the cell functions?
(v) How will concentration of these ions be affected when the cell becomes dead?
For Classes X,XI,XII & B.Sc
Subjects: Physics, Chemistry, Maths & Biology (Comptt. Delhi 2017)
Class XII Chapter -2 Electrochemistry (DPP -02)
Q.1:- The molar conductivity of a 1.5 M solution of an electrolyte is found to be
138.9 S cm2 mol-1. Calculate the conductivity of this solution. (All India 2012)
Q.2:- The conductivity of 0.20 M solution of KCl at 298 K is 0.025 S cm-1. Calculate
its molar conductivity. (Delhi 2013)
Q.9:- Define electrochemical cell. What happens if external potential applied
Q.3:- The conductivity of 0.001 M acetic acid is 4 × 10-5 S/cm. Calculate the
becomes greater than E0cell of electrochemical cell? (All India 2016)
dissociation constant of acetic acid, if molar conductivity at infinite dilution for
acetic acid is 390 S cm2/mol. (Comptt. Delhi 2013) Q.10:- Define the terms conductivity and molar conductivity for the solution of an
electrolyte. Comment on their variation with temperature.
Q.4:- Calculate the degree of dissociation (a) of acetic acid if its molar conductivity
(Λm) is 39.05 S cm2 mol-1.Given: λ°(H+) = 349.6 S cm2 mol-1 and λ°(CH3COO–) = 40.9 Q.11:- The measured resistance of a conductance cell was 100 ohms. Calculate (i)
S cm2 mol-1 (Delhi 2017) the specific conductance and (ii) the molar conductance of the solution.
-1
Q.5:- When a certain conductance cell was filled with 0.1 M KCl, it has a resistance (Molarity of KCl = 74.5 mol/L and cell constant = 1.25 cm ) (Comptt. Delhi 2014)
of 85 ohms at 25°C. When the same cell was filled with an aqueous solution of
Q.12:- Molar conductivity of substance A is 5.9 × 103 S/m and B is 1 × 10-16 S/m .
0.052 M unknown electrolyte, the resistance was 96 ohms. Calculate the molar
Which of the two is most likely to be a copper metal and why?(CBSE 2023)
conductance of the electrolyte at this concentration.[Specific conductance of 0.1 M
+ - 2 -1 2
KCl = 1.29 × 10-2 ohm-1 cm-1] (Comptt. All India 2012) Q.13:- The molar conductivities of NH4 & Cl ion are 73.8 S cm mol & 76.2 S cm
mol-1 respectively. The conductivity of 0.1 M NH4Cl is 1.29 × 10-2 S cm-1 . Calculate
Q.6:- The resistance of 0.01 M NaCl solution at 25° C is 200 Ω. The cell constant of
its Molar conductivity & degree of dissociation.(CBSE 2023).
the conductivity cell used is unity. Calculate the molar conductivity of the
solution.(Comptt. All India 2014) Q.14:- Define degree of dissociation. Write an expression that relates the molar
-4 -5 -1 conductivity of a weak electrolyte to its degree of dissociation.
Q.7:-Conductivity of 2.5 × 10 M methanoic acid is 5.25 × 10 S cm . Calculate its
molar conductivity and degree of dissociation.
Given : λ0(H+) = 349.5 Scm2 mol-1and λ0(HCOO–) = 50.5 Scm2 mol-1. (All India 2015)
Q.8:- The resistance of a conductivity cell containing 0.001 M KCl solution at 298 K
is 1500 Ω. What is the cell constant if the conductivity of 0.001 M KCl solution at
-3 -1
298 K is 0.146 × 10 S cm ? (Delhi 2011)
Q.9:- (b) Consider the figure given and answer the following questions :
(i) What is the direction of flow of electrons?
(ii) Which is anode and which is cathode?
(iii) What will happen if the salt bridge is removed?
