stehiometrija

Submitted by anesa on Fri, 06/19/2015 - 20:38
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Koliko je grama vode potrebno dodati u 500 cm3 40 postotnog rastvora da se dobije 15%-ni rastvor ? Gustina 40 %-tnog rastvora KOH je 1,399 g/cm3 .

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buduci_student - Fri, 06/19/2015 - 20:57

Imas li resenje slucajno

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anesa - Fri, 06/19/2015 - 21:18

1165,8

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Marija 96 - Fri, 06/19/2015 - 22:22

m(H2O)=?

v=500cm3

w1=40%=0,4

ro=1,399g/cm3

w2=15%=0,15

Mr1=ro*V=500cm3*1,399g/cm3 =699,5g

w=ms/mr1

ms=0,4*699,5=279,8g

w2=ms/mr2

mr2=ms/w=279,8/0,15 =1865,33g

m(H2O)=1865,33g-699,5=1165,83g