the conductance at infinite dilution for Nal,CH3COONa and (CH3COO)2 Mg are 10.59, 7.10 and 16.58Scm2 mol-1 respectively at 298K.calculate the molar conductance of Mgl2 at infinite dilution.
Answers
The molar conductance of Mgl2 at infinite dilution is 9.6Scm2mol-1.
Given:
The molar conductance at infinite dilution for Nal, CH3COONa and (CH3COO)2 Mg are 10.59, 7.10 and 16.58Scm2mol-1 respectively at 298 K.
To Find:
The molar conductance of MgI2 at infinite dilution.
Solution:
To find the molar conductance of MgI2 at infinite dilution we will follow the following steps:
As we know,
MgI2 molar conductance is calculated by the formula = molar conductance of (CH3COO)2Mg + 2 × (molar conductance of Nal - molar conductance of CH3COONa).
Because MgI2 = (CH3COO)₂ Mg + 2(Nal - CH3COONa) as:
MgI2 -----> Mg2+ + 2I-.
CH3COONa ------> CH3COO- + Na+
(CH3COO)2 Mg------> 2CH3COO- + Mg2+
Now,
Putting values in the above formula we get,
Molar conductance of Mg12 = 16.58 +
2(10.59-7.10) = 16.58 -2(3.49) = 16.58 - 6.98
= 9.65cm² mol-¹.
Henceforth, the molar conductance of Mgl2, at infinite dilution Is 9.6Scm² mol-¹.