pH vrednost vodenog rastvora NaCH3COO

Submitted by Roy Mustang on Sun, 05/18/2014 - 16:49
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Izracunati pH vrednost vodenog rastvora NaCH3COO koncentracije 0.100 mol/dm^3.. Podatak: K(CH3COOH)=1.8 * 10^(-5)

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milicaradenkovic - Sun, 05/18/2014 - 17:47

CH3COONa-------------------->CH3COO- + Na+

CH3COO- + H2O----------------->CH3COOH+ OH-

Kb=PCH3COOH}*{OH-}/{CH3COO-}

Kb=Kw/Ka=1*10(-14)/1.8*10(-5)=5.55*10(-10)

{CH3COOH}={OH-}=x

{CH3COO-}={CH3COONa}=0.1 mol/l

5.55*10(-10)=x2/0.1

x=(koren(5.55*10(-10)*0.1))=7.45*10(-6)

{OH-}=7.45*10(-6) mol/l

{H+}=Kw/{OH-}=1*10(-14)/7.45*10(-6)=1.34*10(-9) mol/l

pH= -log{H+}=8.87