Răspuns:
Explicație:
c=20%
35og sol. NaOH , c=40%
masa de sare
ms HCl
-se afla md sol. de NaOH
md= c . ms :100
ms= 40 . 350: 100 =140g NaOH
-se afla masa de NaCl
140g yg xg
NaOH + HCl = NaCl + H2O
40g 36,5g 58,5g
x=140. 58,5 : 40=204,75g NaCl
n= 204,75g : 58,5g/moli=3,5 moli NaCl
-se afla masa de HCl
y= 140 . 36,5 : 40=127,75g HCl [ md]
-se afla ms HCl
ms= md.100 : c
ms=127,75 .100 : 20=638,75g sol. HCl
MHCl= 1 +35,5=36,5 ------> 36,5g/moli
MNaCl= 23 + 35,5=58,5------> 58,5g/moli
MNaOH= 23 + 16 +1=40-------> 40g/moli