Hard water contains dissolves compounds such as calcium and magnesium salts.
The calcium and/or magnesium ions in hard water read with soap producing a precipitate called scum.
When water is in contact with rocks some compounds dissolve. If the water contains dissolved calcium or magneisum ions, thesee will react with soap to form scum and so the water is hard.
When it is heated, one type of hard water called temporary hard water prtoduces an insoluble solid called scale. Scale can be desposited in Kettles, boilers and pipes. This reduces the efficency of heating systems, causing blockages.
Calcium compounds are good for our health, helping to develop strong bones and teeth. Calcium may also reduce the risk of heart disease.
scum is formed when soap reacts with dissolved compounds in heard water. When temporary hard water…