12 , 2016-02-29 , 金沢大学人間社会学域学校教育学類 = The School of Teacher Education, College of Human and Social Sciences, Kanazawa University
In the experiments of oxidation reactions of metals carried out in junior high school to ascertain law of definite proportions, there is little that the experimental values of the increase in mass are equal to the theoretical values. One of the main reasons is the mixing of magnesium nitride generated along with magnesium oxide. This can not be avoided basically in the experiments in the atmosphere. The method changing the magnesium nitride generated to magnesium oxide effectively is introduced here. This method of reheating after the addition of water into the products obtained upon the usual heating gave the satisfactory values closer to the theoretical ones. It seems that this also becomes an useful verification means to support the development learning for considering the reasons why the experiments described in textbooks were not successful.