Home
Class 10
CHEMISTRY
In three test tubes A, B and C, three di...

In three test tubes A, B and C, three different liquids namely, distilled water, underground
water and distilled water in which a pinch of calcium sulphate is dissolved, respectivley
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? Justigy your
answer.

Text Solution

Verified by Experts

In test tube 'A' which contains distilled water the length of the foam will be longest.
The sample of water that produces a good amount of foam with soap is called soft water
whereas the one that produces very less foam with soap in called hard water.
The hardness of the water is due to the presence of sulphates, chlorides and bicarbonates of
calcium and magnesium ions in water.
Ground water and distilled water with a pinch of calcium sulphate are hard waters, soap
reacts with the salts present in them and form insoluble precipitates in water.
Promotional Banner

Topper's Solved these Questions

Similar Questions

Explore conceptually related problems

You have been provided with three test tubes. One of them contains distilled water and the other two contain an acidic solution and a basic solution, respectively. If you are given only red litmus paper, how will you identify the contents of each test tube?

A students takes 4 mL of distilled water in each of four test tubes I, II, III and IV, and then dissolves an equal amounts of four differents salts namely NaC1 in I , CaC1_(2) in II , MgC1_(2) in III and KC1 in IV . He then adds 8 drops of the given soap solution to each teat tube and shakes the contents of the test tube 10 times. In which test tubes will enough lather (foam) be formed?

You are provided with three test tubes A, B and C which contain distilled water, acidic solution and basic solution respectively. If you are given blue litmus paper only, how will you identify the contents of each test tube ?