Răspunsuri

2014-10-27T18:15:26+02:00
Ce nu intelegi?
Se aplica formulele concentratiei procentuale.

Cp= (md*100)/ms
Dar ms= md+ mH2O

Din cele doua rezulta ca:

20= (md*100)/(md+400) <=>
 20(md+400)=100md <=>
20 md + 8000=100md <=>
80md=8000 =>
md=100 g


2014-10-27T18:22:33+02:00
C/100 = md/ms
20/100 = md/ms
20/100 = ms/md+400g
20*(md+400) = 100md
20md+ 8000=100md
20md-100md = 8000
-80md = -8000 / *(-1)
80md= 8000
md = 8000/80
md= 100 g