U 250g 5% rastvora Na2CO3 doda se: a) 100g vode, b) 50g soli. izracunati maseni udio soli.
R: a) 3,57% b)20,83%
1)mru=250+100=350g
ms=mr*w=0.05*250=12.5g
w1=ms/mru=12.5/350=3.57% Na2CO3
2) msu=50+12.5=62.5g
mru=250+50=300g
w=msu/mru=62.5/300=20.83% Na2CO3
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1)mru=250+100=350g
ms=mr*w=0.05*250=12.5g
w1=ms/mru=12.5/350=3.57% Na2CO3
2) msu=50+12.5=62.5g
mru=250+50=300g
w=msu/mru=62.5/300=20.83% Na2CO3