Teaching Exploration Of High School Chemistry Experiments Based On Experimental Improvements Under The New Curriculum Standard

Curriculum has always been an important part of school educational system.In recent years,curriculum reform is very popular all over the world.In 2013,China's Education Ministry launched the curriculum revision work.The new curriculum standard in 2017 has updated the teaching contents,condensed the key competencies,and enhanced the guidance of teaching and evaluation.The curriculum standard took the development of the key competencies as the theme,met the diversified development needs of students,reflected the basic and full of time spirits.The aspects of scientific inquiry and innovation awareness in the key competencies inspired students to innovate in the practice,and the aspects of scientific attitude and social responsibility revealed higher pursuits.Chemistry is a subject based on experiments.Experiments can stimulate students'learning interests,cultivate practical and inquiry ability,and develop innovative thinking.However,there may be some problems in the experiments on the textbooks,and some schools are lack of experimental conditions.To give full play to the role of experiment in chemistry learning,it is necessary to improve the experiments in many aspects according to the requirements of the new curriculum standards.At the same time,explore the experiments teaching based on experimental improvements.First,searched literatures and found out the points that need to improve in the current high school chemistry.Then,investigationed and analyzed the actual situation of high school chemistry experiments by questionnaires,interviews and observations.The questionnaires and interviews included students'interests of experiments,the implementation situation of experiments,students'cognition of their experimental ability,and students'attitudes towards experimental improvement and innovation.According to the results of the above investigations,there are some problems in the current high school chemistry experiments,such as some experiments are not environmental-friendly,some experiment devices are complex and lack of connection with life.The research has found some problems of the experiments,and realized that the experiments can attract students'attention and arouse their interests.So the teaching experiments were carried out to activate classroom atmosphere,let students obtain knowledge,develop the chemistry key competencies,and improve their ability.Some representative experimental cases were selected from the suggestions of learning activities of the new curriculum standards for analysis and teaching exploration.According to the principle of experimental design and improvement,the experiments were improved and innovated,and applied to teaching practice.In addition,the teaching methods and learning methods were improved to encourage students to carry out experimental design,experimental improvement and experimental innovation based on the knowledge learned,and the evaluation parts were added.As for the experiment of the properties of sodium carbonate and sodium bicarbonate,the devices in the textbook is a little complex.This study has designed a new scheme by using Y-tube.As for the experiment of reacting with dilute hydrochloric acid,this study has designed a comparative experiment by using tubes and balloons.Other property and identification experiments were added.As for the preparation experiment of ferrous hydroxide,the phenomenon in the textbook is not obvious enough,and the product is easy to oxidize.According to the theory of double hydrolysis,this study has designed new schemes by using branched tube,injector and transparent straw.As for the experiment of iron salts and ferrous salts,only one test method of Fe³⁺was introduced in the textbook.This study has improved the experiment by some magic techniques to increase its interest and added other test methods of Fe³⁺and Fe²⁺.As for the experiment of converting chemical energy into electric energy,this study has used marine organism balls that can be easily found in daily life to improve its interest and intuition.The improvement also can be used in the experiment that converting electrical energy into chemical energy.As for the experiment of catalytic oxidation of ethanol,the scheme in the textbook is not environmental-friendly and the phenomenon is not obvious.According to the theory that use Schiff reagent to test acetaldehyde,this study has designed new schemes by using hard glass tube,branched tube and injector.The above experiments were easy to operate and the phenomenons were obvious,which helped students to obtain knowledge and cultivate the ability of inquiry and innovation.In addition to the classroom experiments,interesting experiments and home experiments were arranged after class.The experiments of solution,colloid and turbid liquid,rock candy growing and plastic making,used common kitchen items.The experiment of acid-base indicator,used petunia to make indicator,also can use other plants.Different regions can choose materials according to local conditions and set up convenient and feasible school-based experiments.The experiment also used the theory that the anthocyanin in lycium barbarum when dissolved in different acidity or alkalinity water can show different colors to compare the acidity and alkalinity of water.The above experiments used the materials from daily life.The operations were easy and were suit to take in home.Experiments helped students to obtain knowledge,enhanced their interests in learning chemistry,and cultivated their practical ability.After the teaching of the experimental improvements,this study made interviews and observations and compared with the previous records,and summarized the ideas of experimental improvements.The experimental improvements were very popular among students,students'interests,abilities and scores were improved,and students'chemistry key competencies were developed.The study has obtained some achievements and it is worth exploring in the future.Under the trend of curriculum reform,the results can also provide references for other researches in related fields.