Alkalinity And Acidity Expressed As CaCO3

To find the equivalent concentration of alkalinity in terms of CaCO3 proceed as follows:

Note: We have reacted the alkalinity species (CaCO3) with the hydrogen ion, since it is the property of alkalinity to react with an acid.

From this reaction, the equivalent mass of CaCO3 is 50. Therefore, a mass equivalent of alkalinity is equal to 50 mass units expressed as CaCO3. For example, 1 gram equivalent of alkalinity is equal to 50 grams of alkalinity expressed as CaCO3.

The determination of the equivalent concentration of acidity in terms of CaC03 is a bit tricky. Calcium carbonate does not react with an 0H- which ought to determine the amount of acidity that CaC03 contains, if it does. But since no reaction can ever occur, CaC03 does not have any acidity; it has alkalinity, instead, as shown by the reaction in Equation (12.85). If CaC03 does not have any acidity, why then express acidity in terms of calcium carbonate? This is one of the biggest blunders in the environmental engineering literature, and it ought to be a big mistake; however, right or not, things can always be made arbitrary and then rationalized—this is what is done and used in practice. Arbitrarily, Equation (12.85) has been made the basis for the determination of the equivalent mass of CaC03 when expressing concentral tions of acidity in terms of calcium carbonate. The rationalization is that the two H+ in Equation (12.85) is equivalent to two 0H-. Thus, the reaction is equivalent as if CaC03 is reacting directly with 0H-. Reasonable? No, but you have to take it. This rationalization is the same as the following rationalization: Pedro and Maria are friends. Maria and Jose are also friends. Therefore, Pedro and Jose are friends. Is this correct? No, because Pedro and Jose are, in reality, irreconcilable enemies. Nonetheless, equivalent mass of CaC03 — 50, no questions asked.

Was this article helpful?

+1 -1
How To Bolster Your Immune System

How To Bolster Your Immune System

All Natural Immune Boosters Proven To Fight Infection, Disease And More. Discover A Natural, Safe Effective Way To Boost Your Immune System Using Ingredients From Your Kitchen Cupboard. The only common sense, no holds barred guide to hit the market today no gimmicks, no pills, just old fashioned common sense remedies to cure colds, influenza, viral infections and more.

Get My Free Audio Book


  • arabella goold
    Why is acidity and alkalinity expressed as caco3?
    2 years ago
  • Roma
    What is acidity is expressed in terms of caco3?
    2 years ago
  • Tiana
    Why acidity and alkalinity as caco3 to measure?
    2 years ago
  • tanja
    Why alkalinity is expressed in terms of caco3 equivalent?
    1 year ago
  • Anita
    Why alkalinity and acidity is expressed in terms of calcium carbonate?
    1 year ago
  • tamela
    What should be the acidity of drinking water as CaCO3?
    1 year ago
    Why alkalinity & acidity are expressed in terms of caco3?
    12 months ago
  • Andreas
    Why caco3 is used to express acidity & alkalinity?
    12 months ago
    Why is caco3 taken as refernce for alkalinity and acidity?
    11 months ago
  • jan
    Why alkalinity is measured as caco3?
    11 months ago
  • Hans
    What is acidity and alkalinity is measured in terms of CaCO3?
    10 months ago
  • piia
    Why hardness is expressed in terms of caco3 equivalent?
    9 months ago
  • Medhane
    Why alkalinity of water is expressed in terms of calcium carbonate equivalent?
    7 months ago
  • fulgenzia
    What is the milliequivalent of CaCO3?
    6 months ago
  • wilibald
    How to express in Caco3 equivalent?
    3 months ago

Post a comment