Răspuns:
Explicație:
120 g Na
react. cu O2-----> Na2O
Na2O react .cu apa
ms NaOH , c= 80%
-se afla masa de Na2O
120g xg
4Na + O2=2 Na2O
4 .23g 2.62g
x= 120 . 2 .62 : 4 . 23 =161,74 g Na2O
-se afla masa de NaOH formata
161,74g yg
Na2O + H2O= 2 NaOH
62g 2.40g
y= 161,74 .80 : 62= 208,7 g NaOH ----- > md sol. de NaOH
ms= md .100 : c
ms= 208,7 .100 : 80=260,8 7 g sol. NaOH
verifica calculele !!!!