Hydroxide
The solubility in water of the other hydroxides in this group increases with increasing atomic number. Magnesium hydroxide Mg(OH) is a strong base (up to the limit of its solubility, which is very low in pure water), as are the hydroxides of the heavier alkaline earths: calcium hydroxide, strontium hydroxide, and barium hydroxide. A solution or suspension of calcium hydroxide is known as limewater and can be used to test for the weak acid carbon dioxide. The reaction Ca(OH) + CO Ca + + OH illustrates the basicity of calcium hydroxide. Soda lime, which is a mixture of the strong bases NaOH and KOH with Ca(OH), is used as a CO absorbent.
Caesium hydroxide
Caesium hydroxide or cesium hydroxide (CsOH) is a chemical compound consisting of caesium ions and hydroxide ions. It is a strong base (pK=-1.76), much like the other alkali metal hydroxides such as sodium hydroxide and potassium hydroxide. In fact, caesium hydroxide is corrosive enough to quickly corrode through glass.