Izračunati pH

Submitted by animallover95 on Mon, 02/17/2014 - 11:27
animallover95's picture
Forums: 
Opšta diskusija

Izračunati pH rastvora dobijenog mešanjem 50 ml rastvora sumporne kiseline, koncentracije 0.2 mol/L i 50ml rastvora natrijum hidroksida, koncentracije  0.3 mol/L... 

milicaradenkovic's picture

milicaradenkovic - Mon, 02/17/2014 - 11:36

H2SO4+2NaOH--------------------.Na2SO4+2H2O

n(kiseline)=c*V=0.2*0.05=0.01 mol

n(baze)=c*V=0.3*0.05=0.015 mol

u visku je kiselina

n1(kiseline)=n(baze)/2=0.015/2=0.0075 mol

n2(kiseline)=n1(kiseline)-n(kiseline)=0.01-0.0075=0.0025 mol

Vu=V1+V2=50+50=100 ml

c(kiseline)=n(kiseline)/Vu=0.0025/0.1=0.025 mol/l

H2SO4------------------>2H+ + SO4-

c(H+)=2*c(H2SO4)=2*0.025=0.05 mol/l

pH= -log(H+)=1.30