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SAI International School
                                                       Class-X

                                               Subject_ Chemistry
                                          Topic- Acids, Bases & Salts
                                  Sub Topic- Properties of Acids & Bases

                                                  LESSON NOTES

                      WHAT DO ALL ACIDS AND ALL BASES HAVE IN COMMON-

                                                  +
                     Every Acid liberates H 3O  (Hydronium) ion in aqueous medium.
                                                   -
                     Every Base liberates (OH)  (Hydroxyl) ions in aqueous medium.

               as per Arrhenius concept.

                Hence all Acids and Bases have Hydrogen atoms in common.

               Activity to show the presence of hydrogen in Acids & Bases-
                  (Refer to Activity 2.8, figure- 2.3, page-22& Video number 4)

               Reactions during electrolysis of dil. HCl-
                                              +            -
                                       HCl(aq)   H (aq)   +   Cl (aq)
               Electrolyte (dil. HCl)              (at Cathode)    (at Anode)


               Reactions during electrolysis of dil.NaOH-
                                       +              -
                NaOH(aq)          Na (aq)   +  (OH) (aq)
                                 Electrolyte (dil.NaOH)              (at Cathode)    (at Anode)

                                                                                                    +
               In both the cases, acids & bases act as electrolytes and liberation of ions[ H &
                     -
               (OH) ]takes place.
               Thus, in the above activity, it is observed that the bulb glowsin both the cases.
                                                                                    +
               This shows the presence of Hydrogen in both – Dilute HClas H ion&
                                         -
               – Dilute NaOH as (OH) ion.

















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