Alternative conception or misconception is one of the problems that often be experienced by the students in science subjects including chemistry due to its abstractness and wide scope to be learned. Previous studies found that students often have misconceptions on strength of acid and base topic such as misconception in determining factor that affect the strength of acid and base, differences between strong and weak acid and base as well as the effect of strength of acid and base on conductivity. To overcome these misconceptions, an online teaching and learning module using 5E instructional model was developed. Analysis, Design, Development, Implementation and Evaluation (ADDIE) model is used for research and development. The module used interactive tools and medias to make students being active and understand chemistry well. This module was validated by five experts in term of module objectives, module content, usability, flexibility, learning activities and language aspects with average is ninety percent. The results prove that the module is very good and has high validity. Therefore, the application of online module for acid and base topic based on 5E (Engage, Explore, Explain, Elaborate, Evaluate) model is suitable to be implemented in online teaching and learning process.

Photocatalytic desulphurization (PDS) is considered as a promising technique to remove hazardous sulphur compounds from fuel oil due to its high catalytic activity, safety, low energy consumption, and low cost. In this work, fibrous silica KCC-1 was synthesized by hydrothermal method followed by incorporation of CuO by electrolysis. The catalyst was used for PDS of dibenzothiophene (DBT). The presence of bicontinuous concentric lamellar morphology with uniform spherical shape was confirmed by FESEM analysis. The phase and crystallinity of the catalysts was investigated by XRD, while the band gap energy was determined by UV-Vis DRS. The PDS performance of CuO/KCC-1 was compared with KCC-1, CuO/SiO2 and SiO2. It was observed that the photoactivity of CuO/KCC-1 was higher than other catalysts (62.6%), which is mainly due to its fibrous morphology and appropriate band gap energy, as well as synergistic role of both CuO and KCC-1. This fibrous type catalyst could be a promising candidate for environmental purification specifically in the sulphur removal.