Question

Sa se determine concentratia procentua a unei solutii de acid acetic stiind ca 200 g din acesta solutie reactioneaza cu 250 ml de solutie de hidroxid de calciu de concentratie 4M .

Answer 1

-calculez moli de hidroxid de calciu dizolvat:
c= n/V
4= n, mol/0,250 l----> n=1 mol
-din ecuatia reactiei deduc moli acid acetic
2mol.................1mol
2CH3COOH + Ca(OH)2---> (CH3COO)Ca + 2H2O
n=.......................1mol
n=2mol---> m= 2molx60g/mol=120g acid acetic dizolvat
-calculez c% din relatia
c= mdx100/ms
c= 120x100/ 200= 60%