A salt is formed when hydrogen ions are replaced by a metal or an ammonium ion in an acid. A base is a material that reacts with an acid to produce just water and salt. When an acid reacts with a base, it produces a salt.Bases are commonly found in household cleansers that are used to remove oil from windows and floors, as well as soaps, toothpaste, egg whites, dishwashing liquids, and household ammonia.Introduction to Acids, Bases and SaltsA substance that tastes sour in water, turns blue litmus red, and neutralises the bases is known as an acid. If a substance’s aqueous solution tastes bitter, turns red litmus blue, or neutralises acids, it’s called a base. Salt is a neutral material that has no effect on litmus in an aqueous solution.Classification of MatterOn the basis ofa) Composition – elements, compounds and mixturesb) State – solids, liquids and gasesc) Solubility – suspensions, colloids and solutionsTypes of mixtures – homogeneous and heterogeneousTypes of compounds – covalent and ionicArrhenius’ Theory of Acids and BasesArrhenius acid – when dissolved in water, dissociates to give H+ (aq) or H3O+ ion.Arrhenius base – when dissolved in water, dissociates to give OH ion.ExamplesAcidsHydrochloric acid (HCl)Sulphuric acid (H2SO4)Nitric acid (HNO3)BasesSodium hydroxide (NaOH)Potassium hydroxide (KOH)Calcium hydroxide (Ca(OH)2)To know more about Arrhenius’ Theory, visit here.Bronsted Lowry TheoryA Bronsted acid is an H+ (aq) ion donor.A Bronsted base is an H+ (aq) ion acceptor.ExampleIn the reaction: HCl (aq) + NH3 (aq) NH+4(aq) + Cl (aq)HCl – Bronsted acid and Cl : its conjugate acidNH3 – Bronsted base and NH+4 : its conjugate acidTo know more about the Bronsted Lowry Theory, visit here.Physical TestGiven are two possible physical tests to identify an acid or a base.a. TasteAn acid tastes sour, whereas a base tastes bitter.The method of taste is not advised, as an acid or a base could be contaminated or corrosive.Example: The flavours of curd, lemon juice, orange juice, and vinegar are all sour. Because t