Three academic years have been considered for the evaluation of the impact of an online tutoring course of general and inorganic chemistry for freshmen students of the University of XX (Italy). The online material mainly consists of video tutorials, other open source web tools and multi-choice self-assessment exercises. During the academic year 2016-2017, the e-learning course was not available yet, but then the online course was first implemented (2017/18) and fully adopted (2018/2019).The online tutoring support was activated alongside a traditional general chemistry course, adopting a blended mode, with the aims of: (i) homogenising freshmen’s chemistry knowledge (ii) fostering the most appropriate method of study in a multi access modality (iii) implementing the Johnstone’s three levels’ knowledge and (iv) increasing students’ self-confidence, by the means of a self-evaluation training process. Differently from previous studies, the online course herein aimed mainly to develop a correct method of study of chemistry topics, with a punctual description of what-and-how to do. The results, i.e. the exam's scores, the time spent in the platform, and the successful percentage of students per year, have been collected and analysed through qualitative and quantitative methods. Apart a general satisfaction of the students perceived by the answers to a survey questionnaire, the analysis of the data shows an increase of 11 % of students passing the final exam within three exam sessions together with an improvement and a positive correlation between the time spent on the platform and the mid-term scores achieved.