The exothermic dissolution of Mg(OH)₂(s) in water is represented by the equation: Mg(OH)₂ <> Mg²⁺ (aq) + 2OH⁻(aq). The Ksp of Mg(OH)₂ is 1.8x10-11. Which of the following changes will increase the solubility of Mg(OH)₂ in an aqueous solution?
1) Increasing the temperature of the solution
2) Decreasing the pressure of the solution
3) Adding an acid to the solution
4) Adding a salt to the solution