Water ionizes to a very small degree into hydronium ions, , and hydroxide ions, :
The very small value of the equilibrium constant, , should give you an appreciation for how few water molecules actually ionize in pure water.
- In neutral solutions, .
- In basic solutions, .
- In acidic solutions, .
But in all aqueous solutions, the product of the hydronium and hydroxide concentrations is equal to . Thus, allows you to calculate from , or vice versa.
5.00×10−3 of are dissolved in water to make 12.0 of solution. What is the concentration of hydroxide ions, , in this solution?