Optical Method of Analysis: Use of Beer’s Law on KMnO_4 Solution
Abstract
Potassium permanganate (KMnO_4) is commonly used as an oxidizing agent and in this experiment, it is used as both the titrant and indicator. A standard of potassium permanganate solution was prepared and computed to be 0.02235 M and was used to titrate a sulfuric acid solution wherein the sample salt was dissolved. The solution was heated to 90°C then titrated until a light pink colored solution was obtained. The experiment focused on determining the percentage of Sodium oxalate (Na2C2O4) in the sample and at the end of the experiment it was found to contain 49.45%.
Experiment 9 focuses on determining the different concentrations of potassium permanganate solutions by finding its absorbance through the use of spectrophotometer. Four known concentrations were prepared; 2.5 x 〖10〗^(-3) M, 6.25 x 〖10〗^(-4) M, 1.25 x 〖10〗^(-4) M, 6.25 x 〖10〗^(-4) M. The solutions were placed on the spectrophotometer to determine absorbance together with the unknown. Distilled water was placed before each trial to ensure the accuracy of results. Determining the concentration of the unknown sample was done by drawing a graph of the concentration against the absorbance and was found to be Introduction
Spectrophotometry is a method to measure how much a chemical substance absorbs light by measuring the intensity of light as a beam of light passes through sample solution. The basic principle is that each compound absorbs or transmits light over a certain range of wavelength. This measurement can also be used to measure the amount of a known chemical substance. Spectrophotometry is one of the most useful methods of quantitative analysis in various fields such as chemistry, physics, biochemistry, material and chemical engineering and clinical applications.
A spectrophotometer is an instrument that measures the amount of photons (the intensity of light) absorbed after