Rastvori

Submitted by Ana100 on Tue, 03/18/2014 - 17:54
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Koje zapremine 70% rastvora gustine 1.4g/cm3 i 20% rastvora nitratne kisjeline gustine 1.1g/cm3 treba pomijesati da se dobije 500 cm3 40% rastvora te kisjeline? Hvala unapred.

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milicaradenkovic - Tue, 03/18/2014 - 18:08

mr1+mr2=600 g              ro(40%)=1.2 g/cm3

ms1+ms2=msu

mru=ro*V=500*1.2=600 g

msu=wu*mru=600*0.4=240 g

mr1=600-mr2

mr1*w1+mr2*w2=240

(600-mr2)*0.7+0.2*ms2=240

420-0.7*mr2+0.2*mr2=240

-0.5*mr2= -180

mr2=180/0.5=360g

mr1=600-360=240 g

V1=mr1/ro1=240/1.4=171.428 cm3 70% rastvora

V2=mr2/ro2=360/1.1=327.27 cm3 20% rastvora