Question

se amesteca 500 ml de solutie de soda caustica de concentratie 20% si densitate 1,22g cu 200g de solutie soda caustica de concentratie 12%. calculeaza concentratia solutiei finale

Answer 1

stim ca c% = mdx100/ms si ro = p = ms /Vs

ms1 = p×Vs = 500×1,22 = 610 g

c%1 = 20%

md1 = ms×c%/100 =>md1 = 610×20/100

md1  = 122 g

ms2 = 200 g

c%2 = 12%

md2 = ms×c%/100 =>md2 = 200×12/100

md2 = 24 g

c%.final = md.tot×100/ms.tot

=> md.tot = md1 + md2 = 122 + 24 = 146 g

ms.tot = ms1 + ms2 = 610 + 200 = 810 g

=> c%.final = 146x100/810 = 18%