broj atoma i masa

Submitted by goranspax on Mon, 04/27/2015 - 13:51
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Opšta diskusija

a) izracunati masu 2dm3 H2 na 15°C i p= 100.7 kPa
b) izracunati broj atoma Na koji se nalazi u 5 g Na

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milicaradenkovic - Mon, 04/27/2015 - 14:08

a) n=p*V/R*T

m=p*V*Mr/R*T

m=100.7*10(3)*2*10(-3)*2/8.314*288.15

m=0.168 g

b) n(Na)=m/Mr=5/40=0.125 mol

N(Na)=n(Na)*Na=0.125*6*10(23)=7.5*10(22)

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goranspax - Mon, 04/27/2015 - 14:50

Zar nije za natrujum 23 ar?

milicaradenkovic's picture

milicaradenkovic - Mon, 04/27/2015 - 16:08

Da jeste

n(Na)=m/Mr=5/23=0.2174 mol

N=n(Na)*Na=0.2174*6*10(23)=1.304*10(23)