When BaCrO4 dissolves, it dissociates like this: BaCrO4 (s) --> Ba2+ + CrO42-
The expression for Ksp is [Ba2+] x [CrO42-]
There is a 1:1 molar ratio between the BaCrO4 that dissolves and Ba2+ and CrO42-
that are in solution. This means that, when 1.08×10⁻⁵ moles per liter of BaCrO4 dissolves, it produces 1.08×10⁻⁵ mol/L of Ba2+ and 1.08×10⁻⁵ of CrO42-. So, applying the expression:
Ksp = (1.08×10⁻⁵ ) x (1.08×10⁻⁵ )
= 1.166 x 10⁻¹⁰
