Calculate $\Lambda _m^o$ for $CaCl_2$ and $MgSO_4$ from the data given in the table below:
Ion and $\lambda ^o / (S \ cm^2 \ mol^{-1})$ Ion and $\lambda ^o / (S \ cm^2 \ mol^{-1})$ $H^{+} : 349.6$ $OH^{-} : 199.1$ $Na^{+} : 50.1$ $Cl^{-} : 76.3$ $K^{+} : 73.5$ $Br^{-} : 78.1$ $Ca^{2+} : 119.0$ $CH_3COO^{-} : 40.9$ $Mg^{2+} : 106.0$ $SO_4^{2-} : 160.0$
| Ion and $\lambda ^o / (S \ cm^2 \ mol^{-1})$ | Ion and $\lambda ^o / (S \ cm^2 \ mol^{-1})$ |
|---|---|
| $H^{+} : 349.6$ | $OH^{-} : 199.1$ |
| $Na^{+} : 50.1$ | $Cl^{-} : 76.3$ |
| $K^{+} : 73.5$ | $Br^{-} : 78.1$ |
| $Ca^{2+} : 119.0$ | $CH_3COO^{-} : 40.9$ |
| $Mg^{2+} : 106.0$ | $SO_4^{2-} : 160.0$ |
According to Kohlrausch law of independent migration of ions:
$\Lambda _{m(CaCl_2)}^o = \lambda _{Ca^{2+}}^o + 2\lambda _{Cl^{-}}^o$
$= 119.0 \ S \ cm^2 \ mol^{-1} + 2(76.3 \ S \ cm^2 \ mol^{-1})$
$= 119.0 + 152.6 = 271.6 \ S \ cm^2 \ mol^{-1}$
$\Lambda _{m(MgSO_4)}^o = \lambda _{Mg^{2+}}^o + \lambda _{SO_4^{2-}}^o$
$= 106.0 \ S \ cm^2 \ mol^{-1} + 160.0 \ S \ cm^2 \ mol^{-1}$
$= 266.0 \ S \ cm^2 \ mol^{-1}$
$\Lambda _{m(CaCl_2)}^o = \lambda _{Ca^{2+}}^o + 2\lambda _{Cl^{-}}^o$
$= 119.0 \ S \ cm^2 \ mol^{-1} + 2(76.3 \ S \ cm^2 \ mol^{-1})$
$= 119.0 + 152.6 = 271.6 \ S \ cm^2 \ mol^{-1}$
$\Lambda _{m(MgSO_4)}^o = \lambda _{Mg^{2+}}^o + \lambda _{SO_4^{2-}}^o$
$= 106.0 \ S \ cm^2 \ mol^{-1} + 160.0 \ S \ cm^2 \ mol^{-1}$
$= 266.0 \ S \ cm^2 \ mol^{-1}$
Explore More
Similar Questions
Explain Kohlrausch law of independent migration of ions.
Medium
View Solution$A$ conductivity cell is filled with $0.01 \ M \ KCl$ and gives a resistance of $484 \ \Omega$. The conductivity of the solution is $0.00141 \ \Omega^{-1} \ cm^{-1}$ at $25^{\circ}C$. What is the cell constant (in $cm^{-1}$)?
Electrical conductance through metals is called metallic or electronic conductance and is due to the movement of electrons. The electronic conductance depends on
Easy
View SolutionWhy does the conductivity of a solution decrease with dilution?
Easy
View SolutionWhich of the following electrolytic solutions has the least specific conductance (in $N$)?
Vedclass Products
For Students
Vedclass Test Series
Mock tests in real JEE/NEET style with performance analysis. 5-day free trial.
Start Free TrialFor Teachers
Exam Paper Generator
Generate Set A/B/C/D exam papers from 7.5L+ questions in 2 minutes. 3 chapters free.
Try FreeFor Institutes
Online Exam Module
Live online exams with unlimited students, 360° analytics & white-label branding.
See Demo