Lather Formation in the Various Sources of Water

Activity: The lather formation in the various sources of water.

Material: 100cm³ of water from the river, rain, borehole, pipe borne and sea, measuring cylinder, test tubes with stoppers, dropper, liquid soap.

Method:

1. Collect about 100cm³ each of river water, rain water, borehole water, pipe borne water and sea water and put them into five (5) different labelled beakers.
2. Measure 20cm³ of water from each sample into a test tube with a stopper. Label each test tube with the source of water in it.
3. Use a dropper to add a drop of the liquid soap to the pipe borne water in a test tube. Cover the test tube with the stopper and shake it well for the liquid soap to lather with the water.
   (a) Record your observation.
   Add more drops of liquid soap into the pipe borne water until a lather form, which lasts for at least a minute.
   (b) Record the number of drops of the liquid soap added for the lather to form and last for at least a minute.
4. Repeat the 3rd step for the other sources of water and record your results in the format like the table below.

With your information given in the test above, must be able to know the following:

(i) Which water sample required the largest number of drops of liquid soap (soap solution) to form a permanent lather?

(ii) Which water sample lathered most readily?

(iii) You can also be able to arrange the samples of water in order of decreasing difficulty to lather with soap.

With the conclusion of the activity above, you will be able to know the types of water for the second use. All the sources which were difficult to lather with soap are known as Hard water and they are: river water, borehole water and the sea water.

The other sources which were able to lather with soap easily are also referred to as Soft water. They are: pipe borne water and rain water.