Question

Se amesteca 80cm cubi de solutie H2SO4 cu conc. 18% si q=1,13g/cm cub cu 120cm cubi solutie de H2SO4 cu conc. 26% si q=1,19g/cm cub. Determinati conc. procentuala si conc. molara a solutiei finale.

Answer 1

Pentru aflarea concentratiei procentuale finale, aplicam urmatoarea formula:
ms1/ms2=(C2-Cf)/(Cf-C1)
ms1Cf-ms1C1=ms2C2-ms2Cf
Cf(ms1+ms2)=ms1C1+ms2C2
Cf=(ms1C1+ms2C2)/(ms1+ms2)
intai ms1=d1*Vs1=1,13×80=90,4g solutie si ms2=d2*Vs2=1,19×120=142,8g solutie
Cf=(90,4*18+142,8*26)/(90,4+142,8)=5340/233,2=22,89%
.....
mdf=md1+md2=(C1*ms1+C2*ms2)/100=5340/100=53,4g H2SO4
nf=mdf/M=53,4/98=0,545moli
Vsf=Vs1+Vs2=80+120=200ml solutie=0,2L solutie
Cmf=nf/Vsf=0,545moli/0,2L=2,725M