Asked by Natash
the pH of a .100 M solution of sodium formate = 8.37. Calculate the value of Ka of formic acid.
okay so I know that the anion of a weak acid is itself a weak base
so A- +H2O---> OH- + HA
pOH =14-8.37 so conc of OH is 10^-5.63
Ka=[OH][HA]/[A-] so we know the conc of OH and A- and then im stuck helppp
okay so I know that the anion of a weak acid is itself a weak base
so A- +H2O---> OH- + HA
pOH =14-8.37 so conc of OH is 10^-5.63
Ka=[OH][HA]/[A-] so we know the conc of OH and A- and then im stuck helppp
Answers
Answered by
DrBob222
Convert to (OH^-) = ?? I get 2.34 x 10^-6 but check me out on that. (HA) is the same. (A^-) is 0.1. Solve for Ka.
Answered by
Natash
I know that part, but why are the conc. of OH and HA the same ?
Answered by
DrBob222
When one 1 mole of A^- hydrolyzes, it produces 1 mole of HA and 1 mole of OH^-. Or you can make up an ICE chart from your equation.
A^- + HOH ==> HA + OH^-
initial:
A^- = 0.1.
HA = 0
OH = 0
change:
HA = +x
OH^- = +x
A^- = -x
equilibrium:
HA = x
OH^- = x
A^- = 0.1-x
etc.
Don't hesitate to follow through if you still don't understand.
A^- + HOH ==> HA + OH^-
initial:
A^- = 0.1.
HA = 0
OH = 0
change:
HA = +x
OH^- = +x
A^- = -x
equilibrium:
HA = x
OH^- = x
A^- = 0.1-x
etc.
Don't hesitate to follow through if you still don't understand.
Answered by
Natash
OHHHH got it, without the ICE chart I sort of get confused. Thanx!
There are no AI answers yet. The ability to request AI answers is coming soon!
Submit Your Answer
We prioritize human answers over AI answers.
If you are human, and you can answer this question, please submit your answer.