This study aims to determine the effect of the application of learning model with advance organizer envisions SETS to increase mastery of chemistry concepts in the high school in Semarang on buffer solution material. The design used in this research is the design of the control group non equivalent. Sampling was conducted with a purposive sampling technique. and obtained a XI 6 scienc... https://www.roneverhart.com/Toshiba-AL13SX-AL13SXB30EN-300GB-15K-RPM-SAS-12Gb-s-512n-128MB-2-5-Hard-Drive/