`100mL` of a colloidal solution is completely precipitated by addition of `5mL` of `1M` `NaCl` solution. Calculate the coagulation value of `NaCl` .

Explanation

Coagulation value is the millimoles of an electrolyte that must be added to `1L` of a colloidal solution for complete coagulation.
`:. 5mL` of `M NaCl=(1)/(1000)xx5=0mol` or `5m mol`
`100mL` of a colloidal solution require `NaCl` for complete coagulation `=5m mol`
Therefore, `1L` of colloidal solution require `NaCl` for complete coagulation `=50m mol`
Therefore, coagulation value of `NaCl=50`