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What is weak electrolyte ? Explain relation between concentration of weak electrolyte and molar conductivity with suitable graph. |
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Answer» Solution :* (a) Weak electrolyte : Electrolytes which gives minimum ionization in its aqueous solution are known as weak electrolyte. They give ionic equilibrium in their aqueous solution. E.g., `CH_(3)COOH, NH_(4)OH` etc are examples of weak electrolyte. * (b) `Lamda_(m)` of weak electrolyte of solution and concentration : For such electrolytes, the change in `Lamda_(m)` with dilution is due to increase in the DEGREE of DISSOCIATION and consequently the number of ions in total VOLUME of solution that contains 1 mol of electrolyte. "ACCORDING to Ostwald.s law of dilution, the conductivity of weak electrolyte solution is significantly increasing with decrease in concentration of solution with weak electrolyte. (e.g., `CH_(3)COOH`)". * (c) Explanation of conductivity on dilution : Dissociation constant of weak electrolyte like acetic acid is low at higher concentration. So change in conductivity of solution of weak electrolyte, increases withthe increase in degree of dissociation. hence, total value of solution with solution of 1 mol of weak electrolyte increases with dilution and molar conductivity significantly increases with the increase in number of ions.  * Limiting molar conductivity of weak electrolyte and measurement of A: * The graph is not linear, but it is curve. in this graph accurate slope is not OBSERVED and so we couldn.t get accurate value for slope and A. * This graph doesn.t possess intercept, so we cant.s obtain the value of `Lamda_(m)^(@)`, because there is no intercept even at zero concentration of `Lamda_(m)` value. |
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