Water hardness determination

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Water hardness determination

By | September 2010
Page 1 of 2
Water Hardness Determination of Tap Water

Lab Report #2

By: Michael A. Vu

September 21, 2010

Introduction:

Titration is the analytical process carried out when the purpose of an experiment is to determine the concentration of an analyte by reacting it with a standardized reagent, known also as the titrant, of known concentration.

The reagent is added to the analyte very carefully and in miniscule amounts until a consistent proof of reaction takes place; such as color change. The end amount of reagent added could then be used to calculate the unknown concentration of the analyte.

EDTA titrations can be performed in several different types of methods such as the potentiometric method, the spectrophotometric method, or simply a direct method based on indicators for the analyte. The method used in this experiment in which the purpose was to monitor the water hardness of tap water was based on indicators for an added metal ion. This method requires the use of an added small metal ion sample for which a good indicator is available.

Water hardness is the cause of dissolving calciums and magnesium salts from rocks and minerals. Since tap water is contaminated H2O, it should be safe to hypothesize that because of the impurities in tap water, the water hardness would be higher than the water hardness of pure H2O. Knowing the level of water hardness of a tap water analyte could assist in determining whether the original source is adequate for human consumption or whether the level of impact it might have on the environment be hazardous.

Experimental: