Acids are those substances which give hydrogen ions by dissolving in water i.e. substances which give hydrogen ions in aqueous solution are called acids. We will discuss about acid, Base and Salt.
Properties of acids
Acids are sour in taste. Good and strong acids are good conductors of electricity. Acids react with metals to release hydrogen gas. They convert blue litmus paper into red litmus paper.
examples and uses
Sulfuric acid: It is used in the refining of petroleum to make explosives and as a liquid in lead accumulator batteries.
Nitric Acid: Used in the manufacture of medicines, in the manufacture of fertilizers, in the manufacture of explosives and in photography as well as in the preparation of amaranth.
Hydrochloric Acid: It is used in making amaranth. (Amalraj is three parts hydrochloric acid and one part nitric acid)
Formic acid: It is used in fruit preservation and as a bactericide. Formic acid acts as a toxic substance in animals like ants, scorpions, bees etc.
Benzoic Acid: It is used in the preservation of foods.
Citric Acid: It is used to clean metals, the main source of which is the juice of lemon or citrus fruits.
Substances that give hydroxide ions (OH) in aqueous solution.
- Properties of alkali
- They are bitter in taste.
- They turn red litmus paper blue.
- Strong alkali is a good conductor of electricity.
- Reacts with acids to form salts.
Sodium Hydroxide: It is use in making soap and in the purification of petroleum.
Potassium Hydroxide: It is use in making soft soap.
Magnesium hydroxide: It is use to remove acidity of the stomach i.e. it acts as an antacid.
The reaction of an acid and a base results in the formation of a salt, while the other compound forms water.
Uses of salts
It is an essential part of human diet which is use in the preservation of pickles and in the preservation of meat and fish.
Sodium bicarbonate: It is use in fire extinguishers.
Sodium carbonate: It is use in the manufacture of glass, in the manufacture of detergents and in the washing of clothes.
Copper Sulphate: It is use in the use of disinfectant which is known as Neela Thothha.
Alum: It is known as potash allan. It is use in the purification of water, in coagulation of blood and in the manufacture of medicines.
The pH value is a number that shows the acidity and alkalinity of a substance. The value of pH ranges from 0 to 14. Solutions whose pH value is less than 7 are acidic. Solutions whose pH value is greater than 7 are alkaline Solutions whose pH value is 7 are neutral solutions.
The pH value is use in industries like alcohol, sugar etc.
|pH value of some common substances|
|Lemon||22 – 24|
|Vinegar||24 – 3.4|
|Alcohol||28 – 3.5|