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Chemistry Forums for Students => Analytical Chemistry Forum => Topic started by: schedler on October 26, 2005, 10:37:30 AM

Title: Groundwater analysis
Post by: schedler on October 26, 2005, 10:37:30 AM

CHEMICAL ANALYSIS OF GROUNDWATER:
For the determination of CHLORIDE I use the argentometric/chromate method of Mohr.
Question:  Does the presence of sulfate (precipitation of silver sulfate) affect the results, giving a too high chloride content?  If so, should I first analyse for sulfate, then subtract the equivalent from the chloride result?
Thanks

Title: Re:Groundwater analysis
Post by: Borek on October 26, 2005, 11:07:38 AM

Perhaps you can precipitate sulfates adding barium nitrate?

Title: Re:Groundwater analysis
Post by: Alberto_Kravina on November 07, 2005, 12:19:26 PM

Yes! You can analyze the sulfates by precipitation with BaCl₂, or Barium nitrate, it's the same thing.
If you want to do a quantitative analysis you can determine the grams/L (or moles/L) of sulfate by gravimetric.

Title: Re:Groundwater analysis
Post by: skyaintsnow on November 15, 2005, 01:15:54 PM

Adding barium nitrate is a better idea, since by adding barium chloride you are importing chloride ions (one more step in calculation, one more source of uncertainty)