Why on dilution the `Lambda_(m)` of `CH_3COOH` increases drastically, while that of `CH_3COONa` increases gradually ?

Explanation

`CH_3COOH` is a weak electrolyte. On dilution, the number of ions increases on dilution due to increase in degree of dissociation as shown below:
`CH_3COOH + H_2O `CH_3COONa` is a strong electrolyte. On dilution, there is not much change in the number of ions. Only interionic attraction decreases. Therefore there is a small increase in `L_(m)`.