Posted by Lucinda on .
what is the pH of a 2.62x10^-1 M NaNO2 solution? NB the pKa for HCN=9.212
and also; what is the pH of a 2.62x10^-1 M HCN solution. NB the pKa forn HCN is 9.212.
CHEMISTRY> HELP QUICK! pls -
For #1, this is a hydrolysis question.
NO2^- + HOH ==> HNO2 + OH^-
Kb = (Kw/Ka) = (HNO2)(OH^-)/(NO2^-)
Make an ICE chart and substitute into the Kb equation. I'm unsure of why you included the pKa for HCN. The pKa you want is HNO2.
For #2, ionize HCN.
HCN ==> H^+ + CN^-
Ka = (H^+)(CN^-)/(HCN)
Set up an ICE chart, substitute into the Ka expression above and solve for H^+, then convert to pH.
Post your work if you get stuck.