Question

intr-un vas se toarna 500ml de solutie de NaOH de concentratie 20% si densitatea ρ=1,22g/cm³apoi se adauga 200g solutie NaOH de concentratie 12%.Calculeaza concentratia solutiei obtinute

Answer 1

Vs1=500mL=500cm³
Cp1=20%
ro1=1,22g/cm³

ms2=200g
Cp2=12%

ro1=ms1/Vs1=>ms1=ro1*Vs1=1,22g/cm³*500cm³=610g. sol. NaOH

Cp1=md1/ms1*100=>md1=Cp1*ms1/100=20*610/100=122g

Cp2=md2/ms2*100=>md2=12*200/100=24g

mdf=md1+md2=122+24=146g

msf=ms1+ms2=610+200=810g

Cpf=mdf/msf*100=14600/810=Calculeaza!