Question

Cata apa trebuie adaugata la 500 g solutie de soda de concentratie 5℅ pentru a o dilua la 2℅? Va rog puneti rezolvarea daca stiti problema

Answer 1

ms= 500
c=5%
c=md*100/ms
md= c*ms/100
md= 5*500/100
md = 25grame
c=2%
2=md*100/(ms+ m apa)
2= 25*100/(500+m apa)
1000+ 2m apa = 2500
2 m apa = 1500
m apa = 750 g