Question

Determinati numarul de moli existenti in:(calcul)

 b) 25g CaCO3    ;    c) 320g SO3   ;  d) 63g HNO3                                    

Answer 1

b)M=40+12+48=100   v=100/25=4                        
 c)M=48+32=80  v=80/320=0,25            
d)M=48+1+14=63  v=63/63=1

Answer 2

25 g CaCO3              se calculeaza masa moleculara
moli                            M=40+12+3.16=100
                                   100g CaCO3-----------1mol CaCO3
                                    25 g CaCO3-------------X
                                   X=25:100=0,25 moli


320 gSO3                  M=32+3.16=80
                                  80g SO3------------1mol SO3
                                    320 g----------------x

                                  x=320:80=4 moliSO3


63 g HNO3                           M=1+14+3.16=63
                                           63g HNO3----------1mol HNO3
                                          63g --------------------x
                                        x=63:63=1 mol HNO3


Sau se aplica formula nr.moli=n=m:M
CaCO3          n=25:100=0,25
SO3                n=320:80=4
HNO3              n=63:63=1