What is the value of Kc?

Question

HS-(aq) + H2O(l) <==> H3O+(aq) + S^2-(aq)

A.) 1.3 x 10^-27

B.) 2.3 x 10^-7

C.) 1.3 x 10^-13

D.) 7.7 x 10^12

E.) 7.7 x 10^26

Answer 1

my text has H2S with a Ka1 = 9.5e-8

(textbooks will vary)

Ka1 is for :  H2S in water--&gt; H3O+  &amp;  HS-

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my text has H2S with a Ka2 = 1e-19

(textbooks will vary)

Ka2 is for :  HS- in water--&gt; H3O+  &amp;  S-2

but I was able to find another reference that has its K2 as K2 = 1.22 x 10-13  (http://www.intute.ac.uk/sciences/referen...

so your answer is: C.) 1.3 x 10^-13

Answer 2

erm you need more values to calculate the Kc, such as the concentration at equlibrium. or at least initial concentration of the reactants....