Karbonske kiseline (zadatak)
Submitted by aliasljubinko on Sat, 04/26/2014 - 19:29

Forums:
Koliko grama cinka se rastvara u 500cm3 20% sircetne kiseline i koliko se cm3 vodonika (n.u) se razvija ( = 1g/cm3).
Hvala unaprijed.
Koliko grama cinka se rastvara u 500cm3 20% sircetne kiseline i koliko se cm3 vodonika (n.u) se razvija ( = 1g/cm3).
Hvala unaprijed.
Zn+2CH3COOH------------------
Zn+2CH3COOH-------------------->(CH3COO)2Zn+H2
w=m/mr
mr=ro*V=500*1=500 g
m=mr*w=500*0.2=100 g
n=m/Mr=100/60=1.67 mol
n(Zn)=n(CH3COOH)/2=1.67/2=0.835 mol
m(Zn)=n*Mr=65*0.835=54.275 g
n(H2)=n(Zn)=0.835 mol
V(H2)=n(H2)*Vm=0.835*22.4=18.704 dm3=18704 cm3