Question

Peste 200ml (densitate 1.8g/cm3) solutie H2SO4 de concentratie 50% se adauga 12g H2SO4 si 100g apa . Ce concentratie procentuala are solutia finala ??? ​

Answer 1

solutia 1:V=200ml=0,02 l

q=1,8 g/cm^3

C=50%

solutia 2:md=12 g H2SO4

100 g apa

Calculăm pentru prima solutie:

q=ms/Vs=>ms1=1,8*0,02=0,036 g H2SO4

C=md/ms*100

50=md/0,036*100

md=ms*100/C

md=0,036*100/50

md=3,6*5

md1=18 g

Calculăm pt a doua solutie masa solutiei

ms2=md2+mH2O=100+12=112 g

Acum calculăm pt solutia finala:

mdf=18+12=30g(md1+md2)

msf=0,036+112=112,036 g(ms1+ms2)

Cf=mdf/msf*100

Cf=112,036*30/100

Cf=3361/100

Cf=33,61%

Bafta!