Question

Se amesteca 300ml solutie de HNO3 de concentratie 1 M avand densitatea de 1,39g/cm3 cu 400g solutie de concentratie 24% ,cu densitatea de 1,145g/cm3 si cu 200g apa. Concentratia procentuala a solutiei obtinute in final este ...?

Answer 1

MHNO3=63g/mol
Vs1=300ml=0.3L
Cm1=1M
ro1=1.39g/cm3
ms2=400g
Cp2=24%
ro2=1.145g/cm3
mH2O=200g

Din Cm1 ==>md1:
Cm=md1/M*Vs(L)==>md1=Cm1*M*Vs=1*63*0.3=18.9g
Din ro1 ==>ms1:
ro1=ms1/Vs ==>ms1=ro1*Vs1=1.39g/cm3*300cm3=417g
Din Cp2 ==>md2:
Cp2=md2/ms2*100 ==>md2=Cp2*ms2/100=24*400/100=96g
Din ro2 ==>Vs2:
ro2=ms2/Vs2 ==>Vs2=ms2/ro2=400g/1.145g/cm3=349.344cm3=0.349344L
Din roH2O ==>VH2O:
roH2O=mH2O/VH2O ==>VH2O=mH2O/roH2O=200g/1g/cm3=200cm3=0.2L
mdf=md1+md2=18.9+96=114.9g
msf=ms1+ms2+mH2O=417+400+200=1017g
Vsf=V1+V2+VH2O=300+200+349.344=849.344cm3=0.849344L
Cpf=mdf/msf*100=114.9/1017*100=11.29%==>Aproximativ 11.30%