Thinking Obstacles And Countermeasures For Solving Comprehensive Problems Of Chemical Reaction Principles In College Entrance Examination

The knowledge of chemical reaction principles includes Energy and optional compulsory course 1,Principles of Chemical Reaction.In the college entrance examination over the years,the comprehensive questions on the principles of chemical reaction are also a required type of exam,with a score of around 13% ～ 15%.The materials for the comprehensive questions on the principles of chemical reaction mostly come from real situations such as industrial production and scientific research experiments.Having the characteristics of extensive knowledge,abstract content,strong comprehensiveness,and unfamiliar situations,students have a relatively low scoring rate,and there are certain thinking obstacles in problem-solving.Therefore,conducting research on students’ problem-solving thinking barriers and proposing corresponding solutions is of great significance for improving students’ learning effectiveness and improving the quality of the college entrance examination.Through statistical analysis of a total of 18 comprehensive questions on the principles of chemical reaction in the national college entrance examination papers and the new college entrance examination papers(Guangdong,Hunan,Hebei,Hubei,Fujian,Liaoning,and Jiangsu provinces implementing the "3+1+2" model)in the past two years.It was found that the content of this type of question is rich,and there are many questions to be asked,and the presentation method is mostly a combination of text information and charts.It mainly combines knowledge of thermochemistry,electrochemistry,and chemical reaction rate and equilibrium.The test questions pay more attention to innovation while emphasizing the basics.Understand the knowledge barriers and thinking barriers that students have in solving chemical reaction principle comprehensive problems through teacher interview questionnaires and student questionnaires.Then analyze the causes of errors through two comprehensive questions on the principles of chemical reaction in the college entrance examination to further clarify students’ thinking obstacles.Further analyze students’ thinking barriers from five aspects: agility,flexibility,profundity,originality,and criticality.In response to students’ thinking barriers,five corresponding solutions are proposed for teachers who want to cultivate students to better answer such questions when explaining them:Improving students’ ability to obtain implicit information;Pay attention to the internal connection of knowledge and cultivate students’ transfer ability;Consolidate the foundation and guide students to build a complete knowledge network;Construct a model for solving chemical reaction principle problems and improve students’ selfmonitoring ability.Among them,seven problem-solving models for constructing chemical reaction principle problems have been constructed,including models for calculating reaction heat and writing thermal chemical equations,models for calculating chemical reaction rates,models for calculating equilibrium conversion rates,models for calculating pressure equilibrium constants,models for writing electrode reaction equations,models for thinking based on chemical equilibrium moving image analysis,and models for thinking about information acquisition and application.Finally,in order to overcome the thinking obstacles in solving the comprehensive questions of the principles of chemical reaction in the college entrance examination,corresponding application research was conducted.Step by step analysis and discussion through the exercise class "Calculation of Equilibrium Constants" to obtain the corresponding problem solving model.In this process,students’ knowledge summary,model construction,and problem-solving thinking abilities will be correspondingly improved,indicating that the proposed solutions are meaningful.