Question

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 $CaC{l}_2$ 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 $CaC{o}_3$ is

• A. $123ppm$
• B. $26ppm$
• C. $0.123ppm$
• D. $38ppm$

Answer 1

The correct option is B $26ppm$

Hence option (b) is correct.

that is 26ppm.