Question

Peste 200 g solutie HCl de concentratie 18,25% se adauga solutie de NaOH de concentratie 20% pana la neutralizarea completa a acidului. Care este concentratia solutiei de sare obtinuta?

Answer 1

mdHCl=200*18,25/100=36,5 g
mH2O= 200-36,5=163,5 g (din solutia de HCl)

HCl  +  NaOH---> NaCl  +  H2O
36,5 g    40g        58,5 g    18 g

solutia de NaOH contine 40g NaOH (md)
msNaOH=md*100/c=40*100?20=200g
mH2O din sol. de NaOH=200-40=160g
ms final este= 200g+ 200g=400g
sau: msfin=mNaOH+mH2O(din solHCl) + mH2O(din sol NaOH)+ mH2O din reactie=58,5+163,5+160+18=400g
c=58,5*100/400=14,62%