Jaslin Ikhsan

The measurement of self-efficacy in the use of VICH-LAB in electrochemistry

A virtual laboratory known as VICH-LAB (Virtual Chemistry Laboratory) has been developed in hybrid learning. This VICH-LAB was used in electrochemistry classes involving much practice work with various tools and materials. VICH-LAB contains a MSDS (Material Safety Data Sheet), tools introduction, interactive practicum, and assignments. The aim of this study was to measure self-efficacy in the use of VICH-LAB. The design of this research was quasi-experimental with a post-test design. Differences among 3 classes with different treatments was observed. The first class used a wet laboratory, the second class used a virtual laboratory integrated hybrid learning approach, and a third class used both of them. All three classes took place during the same academic term and had the same teachers. The variable measured in the three classes was self-efficacy, measured with a questionnaire consisting of 22 items. Self-efficacy scores were significantly different between the class using a wet laboratory and the class that was using the wet laboratory and VICH-LAB as a supplement.A virtual laboratory known as VICH-LAB (Virtual Chemistry Laboratory) has been developed in hybrid learning. This VICH-LAB was used in electrochemistry classes involving much practice work with various tools and materials. VICH-LAB contains a MSDS (Material Safety Data Sheet), tools introduction, interactive practicum, and assignments. The aim of this study was to measure self-efficacy in the use of VICH-LAB. The design of this research was quasi-experimental with a post-test design. Differences among 3 classes with different treatments was observed. The first class used a wet laboratory, the second class used a virtual laboratory integrated hybrid learning approach, and a third class used both of them. All three classes took place during the same academic term and had the same teachers. The variable measured in the three classes was self-efficacy, measured with a questionnaire consisting of 22 items. Self-efficacy scores were significantly different between the class using a wet laboratory and the class ...

Phosphate and nitrate sorption by amine-modified silica as the study of slow release fertilizer

The mud of Lapindo was reported consisted of significant amount of silica that have great capability to adsorb cations and anions due to their large surface areas. The properties of silica can be investigated in the purpose of binding cations and/or anions of micronutrients and releasing them when they are dissolved into water. The measurement of the release rate would give good description of the principle of slow release fertilizer. This research studied preparation of silica from Lapindo mud, that be treated become silica gel (SG) or whose surface were modified by use of (3-Aminopropyl)triethoxysilane (APTES) become amine-modified Silica (AMS). The sorbent was used for adsorption experiments of phosphate (H2PO4 −) and nitrate (NO3 −) ions. Both ions bound the sorbent of AMS through hydrogen bonding. Phosphate formed monolayer surface complexes, but nitrate formed multilayers surface complexes with the sorbent. Desorption results showed that AMS bound phosphate ions stronger than SG. Rate constant of desorption (k) of phosphate by SG and AMS were 0.00507 and 0.000107 g.mmol−1.mint−1 respectively. However, the nitrate desorption by SG were smaller than that by AMS as indicated by k of 0.000268 and 0.000836 g.mmol−1.min−1 respectively