Q75 / 200 · NEET 2023 (Manipur) · Chemistry
Molar conductance of an electrolyte increases with dilution according to the equation:
$\Lambda_{\mathrm{m}}=\Lambda_{\mathrm{m}}^{\circ}-\mathrm{A} \sqrt{\mathrm{c}}$
Which of the following statements are true?
(A) This equation applies to both strong and weak electrolytes.
(B) Value of the constant A depends upon the nature of the solvent.
(C) Value of constant $\mathrm{A}$ is same for both $\mathrm{BaCl}_2$ and $\mathrm{MgSO}_4$.
(D) Value of constant $A$ is same for both $\mathrm{BaCl}_2$ and $\mathrm{Mg}(\mathrm{OH})_2$.
Choose the most appropriate answer from the options given below.
- A(B) and (C) only
- Correct answerB(B) and (D) only
- C(A) and (B) only
- D$(A),(B)$ and $(C)$ only
Solution
$\Lambda_m=\Lambda_m^{\circ}-A \sqrt{c}$
- For strong electrolytes, $\Lambda_{\mathrm{m}}$ increases slowly with dilution.
- The value of ' $A$ ' depends on the type of electrolyte.
- All electrolytes of particular type have the same value for 'A'
e.g. $\mathrm{BaCl}_2$ and $\mathrm{Mg}(\mathrm{OH})_2 \rightarrow 2-1$ electrolytes
Hence, the correct answer is option: 'B'.