Temporary hardness is caused due to the presence of Ca(HCO3)2.
- Ca(HCO3)2: When water containing calcium bicarbonate (Ca(HCO3)2) is heated, it undergoes a chemical reaction where bicarbonate ions decompose to form carbonate ions. The carbonate ions react with calcium ions to form insoluble calcium carbonate (CaCO3) which precipitates out of the solution. This process leads to the formation of scale or deposits in water pipes, appliances, and surfaces.
- Explanation: Temporary hardness is characterized by the presence of bicarbonate ions in water, which can be removed by boiling the water. When water is heated, bicarbonate ions decompose to form carbonate ions, which then react with calcium ions to form insoluble calcium carbonate. This precipitation of calcium carbonate causes the hardness to be removed from the water.
- Effect of Temporary Hardness: Temporary hardness can cause scale buildup in water pipes, water heaters, and other appliances, reducing their efficiency and lifespan. It can also lead to soap scum formation, making it difficult for soap to lather and clean effectively.
- Removal of Temporary Hardness: Temporary hardness can be removed by boiling the water, which causes the precipitation of calcium carbonate. Alternatively, temporary hardness can also be removed by adding lime (calcium hydroxide) or soda ash (sodium carbonate) to the water, which reacts with the calcium ions to form insoluble calcium carbonate.
In conclusion, temporary hardness is caused by the presence of calcium bicarbonate in water, which can be removed by boiling the water or adding chemicals to precipitate out the calcium ions.