This study aimed to analyze the characteristics and feasibility of electronic worksheets based on problem-based learning in the course on acid-base to develop student problem-solving abilities. This was a Research and Development (R & D) using a 4D modified model by Thiagarajan. The 4Ds were Define, Design, Develop, and Disseminate. Product validation was performed by experts. The product practicality test was performed by a reviewer and peer reviewer. Students performed the readability test. Instruments of data collection were product feasibility validation sheets, practicality test assessment sheets, and readability tests. Data analysis techniques were used to calculate the average score, which was categorized according to ideal assessment criteria. The results of the development research showed that an electronic worksheet based on problem-based learning was developed in the form of a website consisting of four learning activities with problem-based learning syntax adapted to the course on acid-base and an electronic worksheet based on problem-based learning in the course on acid-base was very feasible to be used. Based on validation from expert judgments, practicality test assessments from reviewers and peer reviewers, and readability tests by students, including the very good category, meaning that the electronic worksheet is very feasible for learning activities. Therefore, electronic worksheets based on problem-based learning were suitable for chemistry courses on acid-bases to develop problem-solving abilities.
Keywords: electronic worksheets, problem-based learning, acid-base, problem-solving