%X This study aims to analyze the effectiveness of e-module colligative properties of solutions based on guided discovery learning in improving high school student learning outcomes. The research was conducted on class XII students in MAN 1 Padang with 36 students. The type of research used is quasi-experimental with a randomized control-group pretest-posttest design. Data analysis used a t-test. The n-gain value obtained was 0.71 (high category). In conclusion, guided discovery learning based on the chemistry e-module effectively improves student learning outcomes with high criteria. %D 2022 %K E-module, Effectiveness, Guided Discovery Learning, Learning Outcomes %L repounp38306 %P 770-774 %A Alysa Luthfiani %A Yerimadesi Yerimadesi %T Effectiveness of E-Module Based on Guided Discovery Learning on Learning Outcomes of High School Students %V 17 %J Jurnal Pijar MIPA %I Universitas Mataram %N 6