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Mansoura National University
            Pharm D-Clinical Pharmacy Program                 Level 1             Pharm. Anal. Chem. 1 (PC 101)



                                 Mole relationship in balanced equations



                       Determine the number of moles of N O  needed to react completely
                                                                  2
                                                                     4
                                       with 3.62 moles of N H  for the reaction
                                                               2  4
                                            2 N H  + N O                        3 N  + 4 H O
                                              2  4     2  4                    2       2

                                              From the balanced equation:


                                      2 moles N2H4 is equivalent to 1 mole N2O4

                                         2 moles N2H4                 1 mole N2O4

                                            3.62 moles                    X moles

                                           X= (3.62x1)/2 = 1.81 moles N2O4

                                                Chemical Reactions

                   •  Chemical reactions happen all around you & even inside your body!

                   •  Chemical reactions are the changes that occur when chemicals interact with
                       each other to form new and entirely different substances.


                   •  Definition: a process in which one or more substances, the reactants, are
                       converted to one or more different substances, the products.
               Example
               H gas and O  gas                      H 2O liquid
                 2            2

               Parts of A Chemical Reaction
                                ➢  Reactants                                   ➢  Products:

                     •  the substances that undergo                     •  the new substances formed

                               change                                   •  What you end up with

                     •  What you start with


                                                 Reactants change to Products


                 Ex: Carbon + Oxygen change to Carbon dioxide

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