Distinguish between

Question 14 Marks

Write short notes on or Explain:
Man-made detergents

Answer

Detergent which is made by processing naturally available material, soap is a man-made detergent which has been in use since ancient times.
In those days soap was prepared by using animal fat and wood ash.
Therefore two types of soap (a) Hard Soap is used for washing clothes. It is a sodium salt of fatty acids, (b) Softsoap is used for bathing. It is a potassium salt of fatty acids.
It does not cause irritation of the skin.
But we can’t use soap in hard water because soap does not give lather but forms a scum. So, soap loses its cleansing property so now synthetic detergent have taken the place of soap.
Synthetic detergents are obtained by subjecting these raw materials (fats and kerosene) to a variety of chemical processes. These can be used in hard water as well.

Question 24 Marks

Modern cement and Ancient cement

Answer

Modem cement	Ancient cement
1. Cement manufactured from 60% lime, silica 25% and alumina 5%. the rest is iron oxide and gypsum.	1. Romans used to make aqueous cement by mixing volcanic ash in moistened lime. It was very durable.
2. It is the most commonly used cement for Construction work.	2. It is Roman cement volcanic ash prevent cracks from spreading.
3. It is called Portland Cement.	3. It is called Aqueous Cement.

Question 34 Marks

Bath soap and Soap for washing clothes

Answer

Bath soap	Soap for washing clothes
1. Soft soap is used for bathing.	1. Hard soap is used for washing clothes.
2. Soft soap is potassium salt is fatty acids.	2. Hard soap is sodium salt of fatty acid.
3. Soft soap dissolves more easily readily in water.	3. Hard soap do not dissolve easily in water.
4. Now a days many perfumes, moisturizes are mixed to make it more attractive and useful.	4. In this type of soap now a days germicides, anti foaming agents are mixed to make it more useful.

Question 44 Marks

Soap and Synthetic detergents

Answer

Soap	Synthetic detergents
1. Soap is man-made detergent, it is in use since ancient times.	1. Synthetic detergent have taken the place of soap.
2. Soap loses its cleansing property in hard water it does not give lather.	2. Synthetic detergent can be used in hard water also.
3. Soap was prepared by using animal fat and wood ash.	3. Synthetic detergent are obtained by subjecting fats, kerosene to various chemical processes.
4. Variety of soaps are available, soft soap for bathing, hard soap for washing, cleaning.	4. Variety of synthetic detergents are available – Ariel, Surf Excel, etc.

Question 54 Marks

Natural detergents and Man-made detergents

Answer

Natural detergents	Man-made detergents
1. Soap nut (ritha) and soap pod (shikekai) are the natural detergents.	1. Soap is man-made detergent soft soap and hard soap.
2. Natural detergents do not have harmful effect on human skin or on silk or woollen clothes.	2. Soap has effect on skin and cloth because it has chemicals in it.
3. Soap nut, soap pod contain a chemical saponin.	3. Soap has acid in it, soap is sodium and potassium salt of fatty acids.
4. It is naturally available.	4. It is man made using chemicals and oil.

Science Distinguish between