Răspuns:
Explicație:
2NaCl + 2H2O---------->2NaOH + H2 +Cl2 [ a=NaOH ; b=H2; d=Cl2 ]
NaOH + fenolftaleina ------> coloratie rosu-carmin
2H2 +O2=2H2O
H2 + Cl2=2HCl
NaOH + HCl =NaCl + H2O e=NaCl
NaCl + AgNO3=AgCl +NaNO3 f=AgCl
c. xg 20g
2 NaCl + 2H2O ------> 2NaOH + H2 +Cl2
2.58,5g (2+71)g
x=117 . 20 : 73=32,05 g NaCl pur
-se afla masa impura de NaCl
p=mp.100:mi
mi=mp . 100 : p
mi=32,05 .100 : 70=45,78 g NaCl