Determination of Water Hardness By: Diane Krehbiel Abstract: In this experiment, the hardness of an unknown water sample will be determined. The calcium in the water will be measured by performing a titration with EDTA. Eriochrome Black T will be used as an indicator. Standardization of EDTA will be performed first and then the determination of calcium concentration. After standardizing the EDTA, the average molarity was found to be 0.01114 M. The calcium concentration was found to be 203.8 ppm […]
Determination of Phosphates in Water By: David Gould In this experiment, we determined the concentration of phosphorous in an unknown sample. This was done using standards, and then creating a calibration curve to find the unknown concentration using its absorbance. The unknown, number 35 was found to be 0.7355(±0.0589) mg/L phosphorous, which is a relatively small error. Procedure: A Combined Reagent was prepared using 50 mL of 5N sulfuric acid, 5 mL of potassium antimonyl tartrate, 15 mL ammonium molybdate, […]
By: David Gould This experiment consisted of creating various concentrations of copper solutions, and measuring the absorbance of each in an atomic absorption spectrophotometer. The absorbances were used to create a calibration curve, the equation from which was used to calculate an experimental concentration for the unknown I was given. This was found to be 875.3 ppm copper for Unknown #1. Further calculations showed that this gave a hydration number of approximately 2, meaning the unknown was cupric sulfate dihydrate. […]
Introduction This experiment explored aspects of gas chromatography to quantitatively and qualitatively study mixtures. This technique involves separating mixtures to gain a better understanding of the sample’s composition. Gas chromatography uses an injector port that feeds into one of two columns where the mixture is separated. The injected sample will be vaporized by the high temperature and travel down the column. The column itself comes in two varieties: packed and capillary. Packed columns are tubes that have particles that are […]
Fluorescence Spectrophotometry of Riboflavin By: Andrew Tam Introduction This experiment was done to explore an aspect of spectroscopic analysis called fluorescence. This aspect involves shining an ultraviolet light, which will excite the electrons of certain molecules. When these excited electrons returned to their ground (original) state, energy is released and causes the molecule to emit light. This light can then be captured with the use of a detector to measure how intense the compound emits light as a result of […]
Determination of Salicylate via Reaction with Fe(III) By: Andrew Tam Introduction This experiment was performed to study aspects of spectroscopic analysis. To do so, we used an Ocean Optics spectrophotometer to collect optical absorbance spectra for different solutions. In doing so, we also aim to investigate the stoichiometry of reactions using the method of continuous variation. We did so by studying the absorbance of a salicylate complex. Salicylate and salicylic acid are common chemicals found in medications that are used […]
