What Is the Selenide Ion Concentration [Se^2-] for a 0 $K _ { \mathrm { a } } 1 = 1.3 \times 10 ^{- 4}$

Multiple Choice

What is the selenide ion concentration [Se^2-] for a 0.100 mol L^-1 H₂Se solution that has the stepwise dissociation constants of $K _ { \mathrm { a } } 1 = 1.3 \times 10 ^{- 4}$ and $K _ { \mathrm { a } 2 } = 1.0 \times 10^{ - 11} ?$

A) 3.6 × 10^-3 mol L^-1
B) 1.3 × 10^-4 mol L^-1
C) 1.3 × 10^-5 mol L^-1
D) 1.0 × 10^-11 mol L^-1