We have already learned acid and base undergo reaction to produce salt and water. The positive ion of salt comes from the base and that is why the positive ion is known as basic radical. On the other hand, the negative ion comes from acid and that is why the negative ion of salt is called acid radical.
An aqueous solution of salt produced from the reaction between a strong acid and strong base is neutral in nature. For example an aqueous solution of NaCl, Na2SO4 etc. are neutral.
An aqueous solution of salt produced in the reaction between a strong acid and a weak base is acidic in nature. FeCl3, Zn(NO3)2 etc. are examples of the kind.
An aqueous solution of salt produced in the reaction between the strong base and weak acid is basic in nature. Na2CO3, CH3COONa (Sodium acetate) etc. are some examples of the kind.