Hydrosulfuric acid is a diprotic acid, for which ka = and ka = . determine the concentration of sulfide ion in a 0.10 m hydrosulfuric solution.,

a) 5.0 x 10-8 M
b) 3.5 x 10-9 M
c) 7.8 x 10-7 M
d) 1.2 x 10-6 M