Also known as hydrated lime, our lab grade calcium hydroxide is a white crystalline powder. It is slightly soluble in water, soluble in acids, insoluble in alcohol.
Solutions are weakly basic with a solubility of only 0.2g/100ml water. Limewater is a clear, saturated aqueous solution of calcium hydroxide. It reacts readily with carbon dioxide (CO2) forming calcium carbonate.
A mixture of gases can be tested for the presence of CO2 by shaking it with limewater in a clear container. A cloudy calcium carbonate precipitate forms if CO2 is present.
Calcium hydroxide has a number of uses in metallurgy, paper and pulp manufacturing, chemical synthesis and water treatment.