The solubility product of BaSO4 is 1 × 10⁻⁹. What would be the concentration of H2SO4 necessary to precipitate BaSO4?
(a) 1 × 10⁻⁹ M
(b) 2 × 10⁻⁹ M
(c) 3 × 10⁻⁹ M
(d) 4 × 10⁻⁹ M