Question

In the three different test tubes a,b and c three different liquids namely distilled water , underground water and distilled water in which a pinch of clasium sulphate solution is added

Answer 1

Please post the complete question.

The complete question is " In three test tubes A, B and C, three different liquids namely, distilled water, undergound water and  distilled water in which a pinch of calcium sulphate is dissolved, respectively are taken. Equal amount of   soap solution is added to each test tube and the contents are shaken. In which test tube will the length of  the foam (lather) be longest? Justify your answer."

Explanation :

• In test tube A containing Distilled water , the length of foam will be longer  .
• In test tube B --- Under ground water --smaller length of foam
• In test tube C-distilled water + Pinch of CaSO4 --- minimum

length of foam as the soap solution is wasted in reacting with

calcium ions present in test tube c to form insoluble precipitate called scum