Give reasons for the following: 1. Concentrated sulphuric acid is a weaker acid compared to dilute sulphuric acid. 2. An aqueous solution of the salt ammonium chloride is acidic in nature while an aqueous solution if sodium chloride is neutral. 3. Iron(III) chloride is stored in air tight bottles. 4. Acetic acid does not form an acid salt but forms a normal salt. 5. Sulphurous acid forms two types of salts in reaction with an alkali.