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SAI INTERNATIONAL SCHOOL
                                                      CLASS-VII
                                             SUBJECT- CHEMISTRY
                              TOPIC-PHYSICAL AND CHEMICAL CHANGES
                                 SUB TOPIC- DISPLACEMENT REACTION


                                                  LESSON NOTE


               Different Types of Reactions: -
               Displacement reaction-


               The chemical reaction in which more reactive metal displaces another less reactive
               metal from its solution is called a displacement reaction.
               When iron is treated with copper sulphate solution, it displaces copper from the
               solution and itself converted to iron sulphate.
               Equation for the reaction.
               Copper sulphate   + Iron                                             Iron sulphate + copper
                  CuSO4                  Fe                                                   FeSO4                   Cu
               Let us perform an activity.
               Aim- To observe the formation of a new substance on putting an iron nail in copper
               sulphate solution.
               Procedure-
                     Take 100 ml water in a 250 ml beaker.
                     Dissolve a spoonful of copper
                     Stir it well; we get a blue coloured solution.

                     Divide it into two equal parts.
                      In one beaker, put some iron nails and leave it for 30 minutes.

               Observation-
                If we compare the beakers, we will see that the blue colour is changed to green,
               where iron nails are added.
               Inference-
               Blue colour of copper sulphate is changed to green as it forms a new substance iron
               sulphate.

               Similarly, if zinc is added to copper sulphate solution, the colour of the solution is
                       changed to colourless zinc sulphate and copper is deposited at the bottom of
                       the solution.
               Equation for the reaction –
               Zinc    + copper sulphate       Zinc sulphate        +    copper
               Zn             CuSO4                                    ZnSO4                    Cu






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