- calculez masa acidului din solutie
c,/100=md/ms-->7,3/100= md/40---> md=2,92g HCl
-calculez moli si masa BAZA consumata in reactia:
KOH + HCl ---> KCl +H2O
1mol........1mol
56g...........36,5g
m=..............2,92g-----> m=4,48g KOH
-calculez moli baza din solutia data
C,m= n,mol/V.litri---> n= 0,5x0,4= 0,2mol KOH--> m= 0,2x56=11,2g
-diferenta (11,2-4,48)g este masa de KOH CARE reactioneaza cu grasimea
- 34,4g grasime.........6,72gKOH
1g.............................X............................CALCULEAZA
verifica !