Asked by ellen
Calculate the pH of a 0.10 M NaHX salt solution. Ka (H2X) = 2.1 x 10-2 Ka (HX-) = 4.5 x 10-8
Can someone explain the steps to do this please?
Can someone explain the steps to do this please?
Answers
Answered by
DrBob222
The pH will be determined by the hydrolysis of the salt, NaX.
...........X^- + HOH ==> HX + OH^-
initial..0.10.............0....0
change....-x..............x.....x
equil....0.10-x...........x.....x
Kb for the salt = (Kw/Ka) = (x)(x)/(0.10-x)
Kw = 1E-14
Ka is Ka for HX, whatever that is. Solve for x = (OH^-), then convert to H^+ and to pH.
...........X^- + HOH ==> HX + OH^-
initial..0.10.............0....0
change....-x..............x.....x
equil....0.10-x...........x.....x
Kb for the salt = (Kw/Ka) = (x)(x)/(0.10-x)
Kw = 1E-14
Ka is Ka for HX, whatever that is. Solve for x = (OH^-), then convert to H^+ and to pH.