Acid : It is a substance (compound ) which Gives H+ ions in the solution. We can classify acid in following categories. 1) organic acids 2) inorganic acids. 3)strong acid 4) weak acid 1) organic acids : These are carbon containing acids . e.g carboxylic acid ( - COOH), citric acid (C6H8O7) , latic acid (C3H6O6), Oxalic acid (C2H2O4). 2) Inorganic acid : The acids which does not contain carbon. e.g. H2SO4( sulphuric acid) , NH3 ( Nitric acid ), HCl etc. 3) strong acid : The acid which completely dissociates in solution is called strong acid. e.g.HCL , H2SO4, HNO3. 4)weak acid : The acid which does not completely dissolved ( dissociates) In solutions are called weak acid. e.g. acetic acid ( CH3COOH ), latic acid ( C3H6O6), citric acid ( C6H8O7).. I think these are the basic things which we should know about acids. You can buy this book. By using below link. General knowledge book -2021 https://amzn.to/2PDvug1