For the coagulation of 100ml of arsenious sulphide solution, 5ml of IM NaCl is required. Calculate the flocculation value. 

Explanation

Number of millimoles of electrolyte NaCl required to coagulate 100ml of sol
`= 1 xx 5 = 5`.
Number of millimoles of electrolyte required to coagulate 1000 ml of sol
`=5xx(1000)/(100)=50`.
100 The minimum number of moles of electrolyte per litre required to cause precipitation is called . flocculation value. Flocculating value of NaCl = 50 millimole `L^(-1) = 0.05 mol L^(-1)`