Indian Environment Network

Paryavaran.com-Gateway to Indian Environment Market

Hardness of water is caused by bicarbonate and carbonate of calcium and maganesium. calcium carbonate is insoluble salt so why do we consider it as hardness causing agent.

Views: 106

Reply to This

Replies to This Discussion

Since it is insoluble in water therefore causes hardness in water otherwise it would be known as soft water....... so simple.

sorry sir when something is insoluble how can we say the hardness is due to this because hard water is the one in which soap don't form lather with water but the insoluble part can't restrict it with leather formation so it play no roll in hardness. i am still in confusion.

You need to understand basics of hardness:

  • The hardness caused due to the presence of bicarbonates of calcium and magnesium is known as temporary hardness
  • Dissolving these minerals yield calcium and magnesium cations (Ca2+, Mg2+) and carbonate and bicarbonate anions (CO32-, HCO3-).The presence of the metal cations makes the water hard. Temporary hardness can be reduced either by boiling the water, or by the addition of lime (CaOH) through the softening process. Boiling of water promotes the formation of carbonate from the bicarbonate and precipitates calcium carbonate out of solution, leaving water that is softer upon cooling.
  • With hard water, soap solutions form a white precipitate instead of producing lather. This effect arises because the 2+ ions destroy the surfactant properties of the soap by forming a solid precipitate. A major component of such precipitate is calcium stearate, which arises from sodium stearate, the main component of soap:

             2 C17H35COO- + Ca2+ → (C17H35COO)2Ca

  • The hardness caused due to the presence of chlorides and sulphates of calcium and magnesium known as Permanent hardness.
  • Ions causing permanent hardness of water can be removed using a water softener, or ion exchange column. It cannot be removed by boiling

 Hope this will clarify you.

Reply to Discussion

RSS

Paryavaran.com -online webportal to network and do business and philanthropy with Indian Environment Organizations and Professionals


Notes

Network of Indian Environment Professionals LLC

Created by Chandra Kishore Feb 5, 2010 at 3:22pm. Last updated by Chandra Kishore Jan 20, 2020.

Notes Home

Created by Chandra Kishore Oct 5, 2009 at 3:19pm. Last updated by Chandra Kishore Apr 29, 2011.

© 2024   Created by Chandra Kishore.   Powered by

Badges  |  Report an Issue  |  Terms of Service