Describe the following giving one example for each: 

 (i) Detergents 

(ii) Food preservatives 

(iii) Antacids 

(i) Detergents: Synthetic detergent is a cleansing substance that acts similarly to soap but is made from chemical compounds rather than fats and lye. These detergents were developed in order to replace soaps for cleaning, to overcome some of soap's shortcomings. These can be used both in hard and soft water. Example: Sodium p-dodecylbenzenesulphonate

Synthetic detergents can be classified as:

Anionic: Having negatively charged head and widely used due to cost and performance. Uses include:

(i)Laundry detergents

(ii)Dishwashing liquids

(iii)Oven cleaners

Cationic: Having a positively charged head. Uses include:

(i) Cleaning plastics

(ii)Hair shampoos

(iii)Fabric softeners and conditioners

Non-ionic or neutral: Having an uncharged head. Uses include:

 (i)Car shampoos

 (ii)Dishwasher detergents

 (iii)Cosmetics

(ii) Food Preservatives: These are the chemical substances which are added to the food materials to prevent their spoilage and to retain their nutritive value for long periods. Example: Vinegar, salt, sugar, vegetable oil, sodium benzoate (C6H3COONa), and salts of propanoic acid.
Food preservation involves preventing the growth of bacteria, fungi (such as yeasts), or other micro-organisms as well as retarding the oxidation of fats that cause rancidity.

(iii) Antacids: Any drug that is used to counteract the effects of excess acid in the stomach and raise the pH to an appropriate level is called an antacid. Such as sodium bicarbonate, that neutralizes acid