The aim of the study is to develop two web-based worksheets related to "Electrochemistry" topic and to determine the effect of these worksheets on students' academic achievement, logical thinking abilities and attitude towards chemistry. 38 students attending Hacettepe University, Faculty of Education, and Department of Chemistry Education have been participated in these applications. "Redox Achievement Test (RAT)" has been developed by considering behaviors, which are wanted to gain by students, and administered to students. Also "The Logical Thinking Skill Test (LTST)" and "Attitude Scale towards Chemistry (ASC)" have been administered to students as a pre-test. Firstly two web-based worksheets prepared related to electrochemistry topic have been carried out with 7 students as pilot. The worksheets have been rearranged before the application by considering obtained data after expert ideas and pilot application. In the first week of the application, simulation experiments with the computer program called CCI-Project (Creative Chemistry on the Web) ETH (Eidgenossische Technische Hochschule-Zurich) related to worksheets have been showed to students and a discussion setting has been created to Students' gain pre knowledge about the topic. In the second week of the application, the first worksheet has been delivered to all students and they were asked to complete it individually. Students have been asked to do experiment by following instructions, which included in this worksheet. Gaining of concepts included in the worksheet has been tried to provide by considering the findings, which obtained after doing experiment. In the third week of the application, the second worksheet has been delivered to all students and they asked to complete individually. In the forth week of the application, RAT, LTST and ASC have been administered to Students as a post-test. Using paired-samples t-test has compared pre- and post-test results of LTST and ASC and statistical differences have been found. Also it has been observed that after the web-based worksheets application, 32 % of changes in Redox Achievement Post-Test were predicted by LTST and ASC variables by using regression analyze.