Question

three immiscible liquids A,B,C in a test tube. of them which is the most denser liquid​

Answer 1

Answer:Test tube A contains distilled water which is considered as soft water which has no free ions, and thus the length of foam in test tube A will be longest.

Test tube B contains underground water which contains ions like Mg  

+2

,Ca  

+2

, etc. which reacts with soaps to form salts of fatty acids called scum which is insoluble in water and thus the length of foam will be less as compared to that in test tube A.

Test tube C contains distilled water with CaSO  

4

​  

, which contains Ca  

+2

 ions which reacts with soaps to form salts of fatty acids, i.e., scum and thus the length of foam in test tube C will be less as compared to that in test tube A.

Hence the length of foam in test tube A will be longest