Question

Se amesteca 50g de solutie de acid sulfuric de concentratie procentuala masica 10% cu o sulutie de acid sulfuric, de concentratie procentuala masica 60% pt a se obtine o sulutie de concentratie procentuala masica 20%. Determinati masa solutiei rezultate, exprimata in grame. VA ROG E FOARTE URGENT IMI TRB PANA LA 14:20 DAU COROANA!!!

Answer 1

ms1 = 50 g , c% = 10%

ms2 = ? g , c% = 60%

ms.final = ? g , c%.final = 20%

metoda aplicarii regulei dreptunghiului:

c1%=10% ----------------------> 60-20= 40 parti masa sol. 10%

              c.%final=20%  

c2%= 60% -------------------> 20-10= 10 parti masa sol 60%

                             ------------------------------------------------

                                 total = 40+10 = 50 parti msa sol. finala 20%

=>

50 parti sol.finala ......... 40 parti sol 10% ............ 10 part sol. 60%

ms.final ........................... ms1=50 g .......................... ms2 g

= 62,5 g sol.finala 20%

metoda algebrica:

stim ca c% = mdx100/ms

=> md1 = ms1xc1%/100 = 50x10/100 = 5 g

md.tot = md1 + md2 = 5+md2

ms.final = ms1 + ms2 = 50 + ms2

md2 = ms2xc2%/100 = 0,6ms2

=> md.tot = 5 + 0,6ms2

ms.final = md.totx100/c%.final

= (5+0,6ms2)100/20

=> 50+ms2 = (5+0,6ms2)100/20

=> ms2 = 500/40 = 12,5 g

=> ms.final = 50 + 12,5 = 62,5 g