Stalactite a cave it will drip down. When the solution comes into contact with air the chemical reaction that created it is reversed and particles of calcium carbonate are deposited. The reversed reaction is: An average growth rate is a year. The quickest growing stalactites are those formed by a constant supply of slow dripping water rich in calcium carbonate (CaCO) and carbon dioxide (CO), which can grow at per year. The drip rate must be slow enough to allow the CO to degas from the solution into the cave atmosphere, resulting in deposition of CaCO on the stalactite. Too fast
Sodium carbonate sodium sulfate was blended with crushed limestone (calcium carbonate) and coal, and the mixture was burnt, producing calcium sulfide. The sodium carbonate was extracted from the ashes with water, and then collected by allowing the water to evaporate. The hydrochloric acid produced by the Leblanc process was a major source of air pollution, and the calcium sulfide byproduct also presented waste disposal issues. However, it remained the major production method for sodium carbonate until the late 1880s. In 1861, the Belgian industrial chemist Ernest Solvay developed a method to convert sodium chloride to sodium carbonate using ammonia. The Solvay process