Molar Conductivities and their Variation with Concentration NEET Questions

Molar Conductivities and their Variation with Concentration

Molar Conductivities and their Variation with Concentration MCQ Questions

13.
Kohlrausch's law is particularly useful for determining Λm° of:
A.
Strong electrolytes only
B.
Weak electrolytes
C.
Non-electrolytes
D.
Molten salts
ANSWER :
B. Weak electrolytes
14.
Λm°(CH₃COOH) can be calculated using:
A.
Λm°(CH₃COONa) - Λm°(HCl) - Λm°(NaCl)
B.
Λm°(CH₃COONa) - Λm°(HCl) + Λm°(NaCl)
C.
Λm°(CH₃COONa) + Λm°(HCl) - Λm°(NaCl)
D.
Λm°(CH₃COONa) + Λm°(HCl) + Λm°(NaCl)
ANSWER :
C. Λm°(CH₃COONa) + Λm°(HCl) - Λm°(NaCl)
15.
For strong electrolytes, the variation of Λm with concentration is given by Debye-Hückel-Onsager equation:
A.
Λm = Λm° - Ac
B.
Λm = Λm° + A√c
C.
Λm = Λm° - A√c
D.
Λm = Λm° × √c
ANSWER :
C. Λm = Λm° - A√c
16.
A plot of Λm versus √c for a strong electrolyte gives:
A.
A straight line with negative slope and intercept = Λm°
B.
A straight line with positive slope
C.
A horizontal line
D.
A curve passing through origin
ANSWER :
A. A straight line with negative slope and intercept = Λm°
17.
For a strong electrolyte, the limiting molar conductivity is obtained by:
A.
Multiplying conductivity by concentration
B.
Taking value at c = 1 M
C.
Extrapolating Λm vs √c plot to c = 0
D.
Direct measurement at infinite concentration
ANSWER :
C. Extrapolating Λm vs √c plot to c = 0
18.
The decrease in Λm of strong electrolytes with increasing concentration is mainly due to:
A.
Decrease in degree of dissociation
B.
Increase in viscosity
C.
Decrease in number of ions
D.
Inter-ionic attractions (relaxation and electrophoretic effects)
ANSWER :
D. Inter-ionic attractions (relaxation and electrophoretic effects)