pH

Armela's picture

Koliki će biti pH otpine ako u 100cm3 otopine stavimo 20g NaOH i 20g HCl?

milicaradenkovic's picture

NaOH+HCl----------------->NaCl+H2O

n(baze)=m/Mr=20/40=0.5 mol

n(kiseline)=m/Mr=20/36.5=0.55 mol

n1(kiseline)=n(baze)=0.5 mol

n2(kiseline)=n(kiseline)-n1(kiseline)=0.5-0.55=0.05 mol

c(kiseline)=n2(kiseline)/V=0.05/0.1=0.5 mol/l

HCl---------------->H+ + Cl-

pH= -log(H+)=0.3