Question

Ajutoorr!!!
Exercitiul 10...e urgent!!!

Answer 1

c/ 100 = md / ms 
1)  c = 100 x md / ms = 100 x 40 / 250 = 16% m apa = masa solutie - masa dizolvata = 250 - 40 = 210 grame
2) md = c x ms / 100 = 35 x 700 : 100 =245 grame
  m apa = ms - md = 700 - 245 = 455 g apa
3 ) ms = md x 100 / c = 2 x 100 : 40 = 5 grame 
   masa de apa = ms - md = 5 g - 2 g = 3 grame
4)  c / 100 = md / (m apa + md)
   30 / 100 = md / (700+md)
30 (700 +md) = 100 md 21000 + 30 md = 100 md 
21000 = 70 md 
md = 21000 : 70 = 300 grame 
m solutie = md + m apa = 300 + 700 = 1000 g