POINTS TO REMEMER-Class 10 – Science -Chemistry -chapter 2- Acids, Bases and Salt

POINTS TO REMEMER-Class 10 – Science -Chemistry -chapter 2- Acids, Bases and Salt

POINTS TO REMEMER  

➢Everything that tastes sour contains an acid. 

➢ Acetic acid, citric acid, tartaric acid are a few organic acids. Sulphuric acid, nitric acid and hydrochloric acid are examples of inorganic acids. 

➢ Acids turn blue litmus red, whereas bases turn red litmus blue. 

➢ When a solution of an acid contains larger amount of the acid, it is said to be concentrated, while that containing smaller amount of the acid, is said to be dilute. 

➢  Metals like sodium, potassium and calcium react with an acid to liberate hydrogen gas. 

➢ Acids react with bases to produce salts and water. 

➢ Acids react with the carbonates and the hydrogencarbonates to give carbon dioxide gas. 

➢  The hydrogen atoms of an acid which can be partially or completely replaced by an atom or a group of atoms are called replaceable hydrogen atoms. They are also called acidic hydrogen. 

➢ The number of replaceable hydrogen atoms present in a molecule of the acid is known as the basicity of the acid. 

➢ A compound that reacts with an acid to form a salt and water is called a base. ➢ Bases that are soluble in water are called alkalis. All alkalis are bases, but all bases are not alkalis. 

➢ The reaction between an acid and a base is called neutralization reaction. In such a reaction, the acid and the base destroy the properties of each other. 

➢ The number of hydroxyl groups (OH) present in a molecule of the base is called the acidity of the base. 

➢ A salt is a compound formed by the reaction of an acid with a base. 

➢ Na2SO4, CaSO4 and Na3PO4 are normal salts, whereas NaHSO4, NaHCO3, Na2HPO4 are acid salts.    

➢ A strong acid is one which gets almost completely dissociated when dissolved in water to give hydrogen ions, whereas a weak acid gets only partially dissociated in water to give hydrogen ions. 

➢ A strong base gets almost completely dissociated when dissolved in water to give hydroxide ions (OH–), whereas a weak base, when treated as such, gets only partially dissociated to provide hydroxide ions.