The pH of a #5.95\times 10^-1# M solution of a weak base is 11.54. What is the #pK_b# for this base to two decimal places?

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Answer 1 · 2017-11-29T18:35:29

#sf(pK_b=4.69)#

From an ICE table you can use this expression which applies to a weak base:

#sf(pOH=1/2[pK_b-logb])#

b is the concentration of the base.

#sf(pOH+pH=14)#

#:.##sf(pOH=14-11.54=2.46)#

#:.##sf(2.46=1/2[pK_b-log(0.595)])#

#sf(2.46=1/2pK_b+0.1127)#

#sf(1/2pK_b=2.3473)#

#sf(pK_b=4.69)#