1
Ionic conductances of Ba2+ and Cl- ions at infinite dilution are 127 and 76 ohm-1 cm2 mol-1 respectively. Equivalent conductance of BaCl2 at infinite dilution is
- 139.5
- 101.5
- 203
- 279
Answer
(1) 139.5
Solution
∵ As per NCERT (Kohlrausch's law), m = + + + - -
BaCl2 Ba2+ + 2Cl-
⇒ m(BaCl2) = ( Ba2+) + 2 (Cl-)
= 127 + 2 76
= 279 ohm-1 cm2 mol-1
∵ One mole of BaCl2 contains 2 equivalents (total charge on cations = 2)
⇒ eq(BaCl2) = m2
= 2792
= 139.5 ohm-1 cm2 eq-1
Answer: (1)
AIPMT 2000