Valoración De Carbonatos

THEY SUMMARIZE: The alkalinity in the both natural and treated water, usually is caused by the presence of ions carbonates ( CO3= ) and bicarbonates ( HCO3- ), associated with the cations Na+, K+Ca+2y Mg+2. . The alkalinity decides for qualifications of the sample with a solution valued of a strong acid as the HCl, by means of two successive points of equivalence, indicated already be for meanspotenciométricos or by means of the change of color using two warning suitable acid - base.
KEY WORDS: Carbonate, valuation, indicator, pH.

OBJETIVE: To do the corresponding valuations torecognize the method for which the concentrations of the carbonates are situated and the sample to be able like that to analyze problem.
THEORETICAL FRAME: In this method, the alkalinity decides forqualifications of the sample with a solution valued of a strong acid as the HCl, by means of two successive points of equivalence, indicated by means of the change of color of two warning suitable acid -base.

CO3-HCO3 y HCO3-H2CO3
When one adds to the water sample indicator of fenolftaleína and a pink color appears, this indicates that the sample has a major pH that 8.3 and it is indicative of thepresence of carbonates.
It is proceeded to title by valued HCl, until the pink color changes direction to colorlessly, with this, the half of the CO3= is titled.
Immediately they add a few drops oforange indicator of methyl, appearing a yellow coloration and it is continued titling with HCl up to the appearance of a red coloration. With this, one titles the bicarbonates (HCO3-) and theremaining half of the carbonates (CO3=).

If the water samples have a minor pH that 8.3 the qualifications carries out in an alone stage. They add a few drops of indicator of orange of methyl, appearing ayellow coloration and it is proceeded to title by HCl's solution up to the appearance of a red color by it one titles the HCO3-.

PROCEDURE:
Preparar equipo de titulación
Llenar bureta
HCl...