Background: Systematic collection of scientific evidence on the applicability an usability of model and its components is an important aspect of design and development research. Purpose: The aim of this study is to determine external validity of the organic reaction teaching model in terms of its practicability and potentiality in enhancing students' performance scores. Method: A field testing method was conducted across five matriculation colleges in Malaysia by five (5) experts' chemistry lectures who implemented a lesson plan developed based on the model's constructs and then responded to an open ended questionnaire to express their views on the practicability of the model. 40 matriculation Students that participated in the field testing were also evaluated to determine the potentiality of the model on their performance in organic reactions. Four main themes having of many codes and quotations were identified. Results: The analysis of the results indicates that the model is compatible, clear and flexible for teaching organic reactions. Moreover, the model components have the potential of maximizing students' academic performance in organic reaction with an overall score of 84.4% in the organic chemistry tests. Thus, the model was found practicable for teaching and have the potential to minimized students' common errors in organic reaction mechanisms. Conclusions: The findings of this study may similarly work as a reference model in developing modules and measuring instruments to reduce errors in other procedural concepts in chemistry and other science-related subjects.