Question

calculati masa in grame de HCl si cantitatea(moli) de apa necesare prepararii a 400g solutie HCl de concentratie procentuala masica 36,5%.

Answer 1

ms=400g                                                                                                                            c=36,5 la suta                                                                                                                                       md=?
c=md.100:ms                                                                                  md=c.ms:100                                                                                                 md=36,5.400:100                                                                                                       md=146 g                                                                                                                        MHCl=1+35,5=36,5------->1mol=36,5 g                                                                                                                                           1mol HCl---------36,5g                                                                                                  xmol-----------146 g                                                                                                    x=146:36,5=4 moli HCl