Question

Se amesteca 200ml solutie HCl de concentratie procentuala masica 20%(densitatea=1,1g/ml) cu 200 g solutie HCl de c=30% si 100ml apa distilata(densitatea=1g/ml). Calculati concentratia procentuala a solutiei obtinute prin amestecare.

Answer 1

d1=ms1/Vs1 => ms1=d*Vs1=1,1*200=220g solutie HCl
dapa=mapa/Vapa => mapa=100g
c/100=md/ms
=> md1=c1*ms1/100=20*220/100=44g HCl
=> md2=c2*ms2/100=30*200/100=60g HCl
mdf=md1+md2=44+60=104g HCl
msf=ms1+ms2+mapa=220+200+100=520g solutie
cf=mdf*100/msf=104*100/520=20%