Weak Acid/Base Equilibria: C6H5OH & C6H5NH2 K_a & K_b

[APool555]

C_6H_5OH acts as a weak acid and C_6H_5NH_2 acts as a weak base in water. Write equalibrium expressions for K_a and K_b.

 

[josephcollins]

Hi my friend. What you should do here is write first the equilibrium reaction for these two substances ionisation in water, then deduce an expression for Kc-eqm constant. This expression will include the concentration of water, which is constant and thus cancels out of the equation. Then replace Kc by simply Ka or Kb, a new sort of equilibrium constant for these reactions. What you shoulb find is the Ka/Kb is simply the product of the concentrations of the conjugate base/acid and the new acid/base divided by the initial concentration of base/acid. Yours, Joe

 

[Borek]

Try

http://www.chembuddy.com/?left=BATE&right=dissociation_constants

for definitions of Ka and Kb. Just forget about the second dissociation steps.

Chemical calculators for labs and education

BATE - pH calculations, titration curves
CASC - concentration conversions, solution preparation

 

[GCT]

First, show your work, if you had read the text you should at least know how to start.