. The first ionization constant of H2S is
9.1 x 10–8 . Calculate the concentration of HS– ion in its 0.1 M solution. How will this concentration be affected if the solution is 0.1 M in HCl also? If the second dissociation constant of H2S is 1.2 x10–13, calculate the concentration of S2– under both conditions.
Answer: (i) To calculate the concentration of HS– ion:
Case I (in the absence of HCl):
Let the concentration of HS– be x M.
Case II (in the presence of HCl):
In the presence of 0.1 M of HCl, let [HS-] be y M