Răspuns:
Explicație:
ms= 146g sol. HCl , c=20%
r. cu NaOH
masa de NaOH ,p= 80%
-se afla md sol. de HCl
md= c . ms : 100
md= 20 . 146 : 100= 29,2 g HCl
xg 29,2g
NaOH + HCl = NaCl + H2O
40g 36,5g
x= 40 . 29,2 : 36,5=32 g NaOH pura
-se afla masa totala de NaOH
p =mp .100 : mi
mi= mp .100 : p
mi= 32 . 100 : 80=40 g NaOH
MNaOH= 23 +16 +1=40-------> 40g/moli
MHCl= 1+ 35,5=36,5------> 36,5g/moli