| Summary: | 碩士 === 國立高雄師範大學 === 化學系 === 91 === The purpose of the study is to develop the alternate experiments for physical science course in junior high school level. In the study, a simple micro photometer was assembled by LED light source and light sensitive resistor. By using the device, three experiments were investigated.
In the experiment of the stoichiometry between potassium iodide and lead nitrate, the light intensity decreased caused by the precipitate was applied to measure the quantity of the precipitate. Compared to the similar experiment measured by the height of the volume, 1/2000 of chemicals was reduced with better accuracy.
In the experiment of the stoichiometry between magenisium chloride and sodium hydroxide, the similar results were obtained.
In the measurement of methanol in the alcohol, yellow light LED as light source, the detection limit below 100 ppm that lower than the allowance.
The assembled micro photometer can be applied with the advantages of easy assembling, low waste, and low cost.
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