Question

S-au amestecat 50 g solutie cu partea de masa 20% cu 200 g sulutie cu partea de masa 40%.Calculati partea de masa a substantei din solutia obtinuta dupa amestecare.

Answer 1

ms1= 50g
c1=20%

c1=md1/ms1*100
20= md1/50*100
md1= 50*20/100
md1= 10g  

V: c=md/ms*100
    c=10/50*100
    c=10*100/50
    c=20% e adevarat





ms2=200g
c2=40%

c2=md2/ms2*100
40=md2/200*100
md2= 200*40/100
md2=80g


V=c=md/ms*100
     c=80/200*100
     c=80*100/200
     c=40% (corect)