Visual Chemistry Experiment Using Agar Gel in Senior High School

Abstract

Students’ interest in chemical experiments is caused by observing changes through chemical reactions. The author investigated three types of experiments using agar gel, which allows observing the reaction process over a relatively long period of time. Firstly, the process by which acidity, neutrality, and basicity are determined by the properties of salt produced in the neutralization reaction between acid and base was investigated. Secondly, the appearance of precipitate lines formed by the reaction of calcium and barium ions with carbonate and sulfate ions was observed. Thirdly, it is observed that precipitates are formed depending on the strength of alkalinity due to the reaction between metal ions and an aqueous sodium hydroxide solution.