Broj molova

dejanbr1's picture

Koliko ima molova u 1l rastvora dobijenog mesanjem 300 ml rastvora glukoze (C6H12O6) koncentracije 72 g u litru i 200 ml rastvora koji u 1 l sadrzi 27 g iste supstance?

milicaradenkovic's picture

y1=m1/V=72/1=72 g/l a y2=m2/V=27/1=27 g/l

c1=y1/Mr=72/180=0.4 mol/l

c2=y2/Mr=27/180=0.15 mol/l

n1=c1*V1=0.4*0.3=0.12 mol

n2=c2*V2=0.2*0.15=0.03 mol

nu=n1+n2=0.03+0.12=0.15 mol

Vu=V1+V2=300+200=500 ml

cu=nu/Vu=0.15/0.5=0.3 mol/l i to je 0.3 mola