Question
Calculate the equilibrium constant for the following reaction of a weak acid and base HF + NH3 <=> NH4+ + F-
given Ka (HF) = 6.9 x 10^-4 and Kb (NH3) = 1.8 x 10^-5 and Kw = 1.0 x 10^-14
given Ka (HF) = 6.9 x 10^-4 and Kb (NH3) = 1.8 x 10^-5 and Kw = 1.0 x 10^-14
Answers
I would look at this.
Write Ka expression for HF.
Write Kb expression for NH3(aq)
Write Kw expression for H2O.
Now, Write Keq expression for the reaction. Substitute for (NH4^+) from the Kb expression, substitute for the (F^-) from the Ka expression and cancel similar terms. I think that will get Keq in terms of Kw, Ka, and Kb. You will need to remember that (H^+) = (F^-) for the last step.
Write Ka expression for HF.
Write Kb expression for NH3(aq)
Write Kw expression for H2O.
Now, Write Keq expression for the reaction. Substitute for (NH4^+) from the Kb expression, substitute for the (F^-) from the Ka expression and cancel similar terms. I think that will get Keq in terms of Kw, Ka, and Kb. You will need to remember that (H^+) = (F^-) for the last step.
much thanks!!!
Related Questions
A.CALCULATE THE CRYOSCOPIC CONSTANT OF H2O. USE IT TO ANSWER THE FOLLOWING: a WEAK ACID HX is dissol...
Ka for a weak acid HA = 3.46x10^-8, calculate K for the reaction of HA with OH-
HA + OH- = A- + H...
Write the balanced NET IONIC equation for the reaction that occurs when ammonium chloride and calciu...
The same quantity of each solute is added to water. Which solution will have the greatest number of...