Page 14 - Chemistry
P. 14

25                                                                                                    26






                                           According to the Law of                                                                              According to the Law of


                                Conservation of Mass, how many                                                                       Conservation of Mass, how many


                                grams of hydrogen are needed?                                                                               grams of sulfur are needed?




                                              2H + O → 2H O                                                                                                 Fe + S → FeS
                                                                    2
                                                                                        2
                                                      2

                                              ___ g  + 15 g  → 40 g                                                                                     75 g + ___ g → 250 g





                                                                                             © The Science Duo                                                                                     © The Science Duo











                                                                                                     27                                                                                                    28






                                         According to the Law of                                                                                 According to the Law of


                                      Conservation of Mass, how                                                                              Conservation of Mass, how


                                     many grams of hydrochloric                                                                              many grams of magnesium


                                                 acid are needed?                                                                                              are needed?


                                           2H +  Cl → 2HCl                                                                                   4Mg  +  2O → 4MgO

                                                                      2
                                                   2
                                                                                                                                                                               2
                                           65 g   +   35 g   →                          ___ g                                                   ___ g     +    175 g   →                           500 g



                                                                                            © The Science Duo                                                                                      © The Science Duo
   9   10   11   12   13   14   15   16   17   18   19