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Submitted by Dušan on Sun, 01/12/2014 - 14:02
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Koliko treba odmeriti MgSO4·7H2O,a koliko vode za pripremanje 160cm3 5%-nog rastvora MgSO4 gustine 1,032 g/cm3?

 

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milicaradenkovic - Sun, 01/12/2014 - 14:33

mr=ro*V=1.032*160=165.12 g

ms(MgSO4)=mr*w=165.12*0.05=8.256 g

8.256 g-------------------120.366 g/mol

x g---------------------------246.482 g/mol

x=246*8.256/120=16.9 g MgSO4*7H2O

m(vode)=mr-ms=165.12-16.9=148.22 g

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Dušan - Sun, 01/12/2014 - 14:54

Hvala!