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The new experimental method described above can help in teaching and learning acid-base concepts. It is suitable for experimental work performed by pupils and can be used also for teacher´s demonstrations. In this method, a soft medium based om flour is used as a reaction medium to carry out chemical reactions that can normally run in water solution. No laboratory glassware is necessary for the experiments, and there is no risk of spillage. The experiments can be done anywhere, safely and individually also in a larger group of pupils. Micro or semi-micro quantities of chemicals are employed, andthe medium, which has been used, can be safely disposed afterwards. V članku je opsana nova eksperimentalna metoda, ki jo lahko uporabimo pri razvijanju pojmov s področja kislin in baz pri pouku kemije. Pri tej metodi uporabimo namesto vodnih raztopin, ki jih običajno uporabljamo pri eksperimentiranju s kislinami in bazami, mehki medij na osnovi moke, ki ima hkrati vlogo topila in vlogo trdnega nosilca. V članku so opisani primeri priprave reagentov, disperzij različnih spojin v mehkem mediju, in primeri reakcij s pripravljenimi reagenti. Reakcije z reagenti v mehkem mediju izvajamo brez topil in za izvedbo eksperimentov ne potrebujemo posode. Učenci lahko te eksperimente izvajajo samostojno in varno. Uporaba semimikro oziroma mikro množin kemikalij pri tej eksperimentalni metodi omogoča, da preostanke reagentov lahko odstranimo skupaj s komunalnimi odpadki. |
