chemistry - water

key points

• hard water contains dissolved compounds such as calcium and magnesium salts.
• the calcium and/or magnesium ions in hard water react with soap producing a percipitate called scum.
• temporary hard water can produce a solid scale when its heated, reducing the effeicency of heating systems like kettles.
• hard water is better than soft water for developing teeth and bones. it may also prevent heart disease.
• soft water does not contain salts that produce scum or scale.
• hard water can be soften by…