Question

In 500 mililitri solutie de sare cu concentratia 10% si densitatea solutiei 1.4 g/l , se adauga 2.3 kg apa . Claculeaza concentratia finala

Answer 1

ro = p = ms / Vs, cred ca p = 1,4 g/ml

=> ms = p x Vs = 0,5 x 1,4 = 700 g sol.

c = mdx100/ms => md = cxms/100 = 10x700/100 = 70 g

=> ms.fin = ms1 + m.apa = 700 + 2300 = 3000 g

md = 70

=> c.fin% = 70x100/3000 = 7%