The Complexometric Determination of Calcium and Magnesium in Limestone Using a Laser Photometer for Endpoint Identification

• Daniel M. Mossman ^[1] ; Robert G. Kooser ^[1] ; Lawrence E. Welch ^[1]
  1. [1] Knox College

     Knox College

     Township of Galesburg City, Estados Unidos

     
• Localización: Journal of chemical education, ISSN 0021-9584, Vol. 73, Nº 1 (January), 1996, págs. 82-85
• Idioma: inglés
• Texto completo no disponible (Saber más ...)
• Resumen

  • An alteration of the classic complexometric titration of calcium and magnesium with EDTA was made to incorporate a laser photometer for endpoint detection. The photometer utilized a He-Ne laser, which allowed the red to blue transition of the calgamite indicator to be followed by monitoring the change in beam absorbance. A photodiode and an inexpensive computer interface were used to record the intensity of the transmitted laser beam as a function of time. This method makes the experiment much more accessible for students suffering from color blindness.