Development of Problem-solving e-Worksheet to Improve Problem-solvingSkills in Reaction Rate Materials. This study aims to know e-worksheet feasibility for improving students' problem-solving skills in rate reaction materials. The reaction rate is also considered an abstract subject that requires a high ability to understand, memorize, calculate, analyze, and actively practice. Understanding phenomena associated with chemical concepts requires a special skill, it is a problem-solving skill. One way to train students' skills is to conduct appropriate learning and suitable media. This study uses Research and Development (R&D) with limited testing phases, ADDIE method, and descriptive-analytical models. Problem-solving e-worksheets are feasible based on validity, practicality, and effectiveness aspect. Validity reviewed by content and construct. The result validity is 4, which means it is very valid. Practicality reviewed by student responses which show 90-95% positive response results, so e-worksheets are considered in very practice category. Effectiveness is reviewed from gain results from understanding problem is 0,77; devising a plan 0,73; carrying out the plan 0,71; and looking back 0,46.