Q5
A 500 ml. sample of the effluent from a water softener required 6 drops of standard soap solution to produce a permanent lather. The shop solution had been calibrated against an artificial hard water solution containing 0.136 g of CaCl2 per liter. On the average it required 28 drops of standard soap solution to lather 500 ml. of the artificial sample. Then the hardness of effluent sample in terms of ppm of CaCo3 is