Question

Doar punctul a), cel puțin un exemplu. Mulțumesc

Answer 1

Răspuns:

S1-> S2   sol se concentreaza ,fie prin adaugarae de zahar,fie prin evaporarea apei

c1=20%

ms1=500g--------> md1= c1xms1/100= 100g;  m,apa1= 500-100=400g  

c2= md2x100/ms2= md1x100/(ms1-m,apa),    deoarece md2=md1

35/100= 100/(500-m,apa)---> m,apa= 214g

md2=100g   ms2= 500-214-> 286g   m,apa2= 286-100=186g

S2-->S3   sol. se dilueaza , adaugand apa

c2= 35%  md2=100g   ms2=286

c3=md3x100/ms3= md2x100/(ms2+m,apa)

25/100= 100/(286+m,apa)......> m,apa= 114g

ms3= 286+114=> 400g, m,d3= md2=100g     m,apa3= 400-100g=300g

S3---> S4      se concentreaza , adaugand md zahar

md4=md3+md=100+md g

ms4= ms3+md=400+md

c4/100= md4/ms4

40/100= (100+md)/(400+md)        calculeaza md !!!!!

Explicație: