Kohlrausch Law (Electrochemistry) MCQ Questions for NET, GATE & JAM - Download PDF

Kohlrausch Law MCQ Questions
for CSIR UGC NET, JAM & GATE

Electrochemistry
Topic wise Assignment-2

QUIZ              PDF

Q1. The molar conductivities at infinite dilution for Na₂SO₄, K₂SO₄, KCl, HCl and HCOONa at 300K are 260, 308, 150, 426 and 105 S cm² mol^-1 respectively. Hence Λ°_m for formic acid in the same unit will be

[NET Dec 2011]

(a) 381
(b) 405
(c) 429
(d) 531

Q2. Kohlrausch's law is applicable to a dilute solution of

[NET Dec 2012]

(a) Potassium Chloride in Hexane
(b) Acetic acid in water
(c) Hydrochloric acid in water
(d) Benzoic acid in benzene

Q3. If the concentration (c) is increased to 4 times its original value, the change in molar conductivity for strong electrolytes is (where b is Kohlrausch's constant)

[NET June 2013]

(a) 0
(b) b√c
(c) 2b√c
(d) 4b√c

Q4. The limiting molar conductivities of NaCl, NaI and RbI are 12.7, 10.8 and 9.1 mS m² mol^-1 respectively. The limiting molar conductivity of RbCl in mS m² mol^-1 would be

[NET Dec 2013]

(a) 32.6
(b) 7.2
(c) 14.4
(d) 11.0

Q5. In the graph, according to Kohlrausch's law, the current option is

[NET June 2014]

(a) A is weak electrolyte, B is strong

(b) A is strong, B is weak

(c) C is strong, D is weak

(d) C is weak, D is strong

Q6. In Kohlrausch's law, Λ_m= Λ°_m-K√c, Λ°_m and K

[NET Dec 2015]

(a) Depend only on stoichiometry
(b) Depend only on specific identity of electrolyte
(c) Are independent of specific identity of electrolyte
(d) Are mainly dependent on specific identity of electrolyte and stoichiometry respectively

Q7. If the specific conductance of a springily soluble (1:1) salt (MW=200 g mol^-1) in it's saturated aqueous solution at 25°C and that of water is 1.5 x 10^-5 Ω^-1 dm^-1; and the ionic conductance for it's cation and anion at infinite dilution are 0.485 Ω^-1 and 1.0 Ω^-1 dm² mol^-1 respectively; the solubility (in g L^-1) of the salt in water at 25°C is

[NET Dec 2016]

(a) 1 x 10^-6
(b) 1 x 10^-3
(c) 2 x 10^-1
(d) 2 x 10^-4

Q8. Λ°_m(H₂O) is equivalent to
A. Λ°_m(HCl) + Λ°_m(NaOH) - Λ°_m(NaCl)
B. Λ°m(HNO₃) + Λ°_m(NaNO₃) - Λ°_m(NaOH)
C. Λ°_m(HNO₃) + Λ°_m(NaOH) - Λ°_m(NaNO₃)
D. Λ°_m(NH₄OH) + Λ°_m(HCl) - Λ°_m(NH₄Cl)
(a) A only
(b) A and D
(c) A, C and D
(d) B and D

Q9. Molar conductivity of ionic solution depends on
A. temperature
B. distance between electrodes
C. concentration of electrolytes in solution
D. surface area of electrodes
(a) A, B and C
(b) A and D
(c) B and D
(d) A and C

Q10. Ionic mobilities of NH₄⁺ and HCO₃^- are 6 x 10^-4 and 5 x 10^-4 V^-1 cm² s^-1. Calculate the transport number of NH₄⁺ and HCO₃^- respectively.
(a) 0.45, 0.55
(b) 0.40, 0.60
(c) 0.60, 0.40
(d) 0.55, 0.45

Answer Key

Q1.b Q2.c Q3.b Q4.d Q5.c Q6.d Q7.c Q8.c Q9.d Q10.d

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