World Journal of Chemical Education, 2017, Vol. 5, No. 5, 168-174 Available online at http://pubs.sciepub.com/wjce/5/5/5 ©Science and Education Publishing DOI:10.12691/wjce-5-5-5 Designing Experimental Exercises Used for Teaching Chemistry in High School C.C. Giac 1,* , L.H. Hoang 2 , N.T.P. Lien 3 , P.H. Thanh 4 1 Faculty of Chemistry, Vinh University, Vinh City, Vietnam 2 Faculty of Chemistry, Dong Thap University, Dong Thap Province , Vietnam 3 Faculty of Environmental Science, Saigon University, Ho Chi Minh City, Vietnam 4 Nguyen Duc Mau High School, Nghe An Province, Vietnam *Corresponding author: giaccc@vinhuni.edu.vn Abstract This study has represented a model of experimental exercises in teaching chemistry. The model, which is the type of exercise associated with chemistry laboratories that when students answer them, they have to get the basic skills of practice chemistry. By analyzing the model of experimental exercises, we have proposed two underpinnings to design these exercises. On that basic, we proposed the way to design new experimental exercises. These methods are analyzed in detail and there are the attached application so that teacher can apply to design the same cases. Based on the proposed methods, we have designed sample exercises used in high school chemistry teaching. The exercises were solved clearly and evaluation of chemistry practical skills for students. This type of exercises is always attractive to create certain excitements for teachers and students in the teaching and learning chemistry in high school. Keywords: teaching chemistry, experimental exercises, chemistry practical skills, laboratory Cite This Article: C.C. Giac, L.H. Hoang, N.T.P. Lien, and P.H. Thanh, “Designing Experimental Exercises Used for Teaching Chemistry in High School.” World Journal of Chemical Education, vol. 5, no. 5 (2017): 168-174. doi: 10.12691/wjce-5-5-5. 1. Introduction 1.1. Model of Experimental Exercises of Chemistry Chemistry experimental exercises are problems that students have to apply their practised knowledge in the laboratory when they answer them. Model of experimental exercises below. condit ions r equir ement s 1/ The thinking activities 2/ The prctical skills in lab Data about chemistry practices Requirements on chemistry practices (Given) (Unknown) Ex per iment al exer cise 1.2. Underpinnings of Designing Chemistry Experimental Exercises From the model above, we infered 2 underpinnings for designing practical exercises of chemistry [1]. Theoretical underpinning: including the contents of chemistry theory [2]. Experimental underpinning: including the experimental contents and practicing skills in the lab [3]. Thus, in order to design experimental exercises may stem from: (1) The basic knowledge and practicing skills to train for students [4]. (2) Common mistakes of theory and practice that students often make. (3) Some basic exercises available. Based on the underpinnings and the starting point above, we can build an chemistry experimental exercise with typical basic properties (called as the original exercise). Applying grap method combined with the modular approach, we can modify the original exercise into some different exercises based on some fundamental principles below. Principle 1: Inverse between conditions and requirements Principle 2: Change conditions Principle 3: Change requirements Principle 4: Change both conditions and requirements Principle 5: Combination several exercises Principle 6: Transfer essay exercises (short answer or extended response) to multiple choice test and vice versa. 2. Method - Designing Exercises We can consider an example for teaching halogen chapter of inorganic chemistry. After students have completed this chapter, teachers should check students’ practical skills of collecting chlorine gas in the laboratory. Teachers can build the following original exercise.