This research is part of a research project to help improve students' argumentative skills in chemistry subjects. This research is part of the development of argumentation-based teaching materials while other studies have developed learning models, teaching materials and a collection of argumentation questions. The purpose of this research was to determine the process of developing students' e-worksheets, the feasibility of students' e-worksheets based on concept and practitioner perceptions, and the effectiveness of students' e-worksheets that were developed as teaching materials based on the Toulmin argumentation pattern. Product trials were conducted at state senior high schools 11 Jambi City. The results of the practitioner's eligibility based on the teacher's response are in the very good category and students from both groups have a correlation in the "high" category. The effectiveness test is seen from the average N-Gain score of the experimental class in the quite effective category. There is a significant difference between the experimental class and the control class which can be seen from the difference in learning outcomes of the experimental class (using students' e-LKS based on the Toulmin argumentation pattern) higher than the control class (not using e-LKS).
The new kinetics equation has been proposed and applied to the sorption of Cd(II) and Zn(II) onto green sorbent horse dung humic acid (HD-HA). This work aims to study the new kinetics equation and to compare its parameters with Lagergren and Ho kinetics equation in the same system. HD-HA was extracted and purified by Stevenson’s methods and then characterized by detection of its functional group, UV-Vis spectra, and total acidity. The sorption study of this work was investigated by batch experiment in pH optimum 5. Langmuir’s monolayer sorption capacity (b) of Cd(II) and Zn(II) onto HD-HA was 1.329×10-3 and 1.070×10-3 mole.g-1, respectively. Langmuir equilibrium constant (KL) of Cd(II) and Zn(II) sorption was 5,651 and 6,399 (mole/L)-1, respectively. The kinetics parameters were determined by Lagergren, Ho, and the new kinetics equation. The best linearity (R2) and the most fitted sorbed metal ion in equilibrium (xe) with the experimental data was the Ho kinetics equation. However, the correct value of sorption rate constant (ka) was not really known, because the ka resulted from Ho and Lagergren kinetics equation can not be compared with another parameter and there is no scale to measure the correctness of this value of ka. In this work, the correctness value of ka of the new kinetics equation can be measured by ka/kd equal to K, and this K should be equal to KL. The values of K of Cd(II) (3,452 (mole/L)-1) and and Zn(II) (10,898 (mole/L)-1) were quite similar with KL. Additionally, the value of intercept from linear regression of this new kinetics equation (Cd(II) = 6.8517; Zn(II) = 6.0408) was highly similar with the manually calculation of -ln(xe/ab) (Cd(II) = 7.0638; Zn(II) = 6.9838). These new kinetics equations also reveal that Lagergren sorption rate constant (kLag) is the complex function of ka(ab-xe2)/xe). Copyright © 2018 BCREC Group. All rights reservedReceived: 21st November 2017; Revised: 28th June 2018; Accepted: 3rd July 2018How to Cite: Basuki, R., Ngatijo, Santosa, S.J., Rusdiarso, B. (2018). Comparison the New Kinetics Equation of Non-competitive Sorption Cd(II) and Zn(II) onto Green Sorbent Horse Dung Humic Acid (HD-HA). Bulletin of Chemical Reaction Engineering & Catalysis, 13 (3): 475-488 (doi:10.9767/bcrec.13.3.1774.475-488)Permalink/DOI: https://doi.org/10.9767/bcrec.13.3.1774.475-488
Argumentation skills have been minimally fostered in the worldwide science classrooms that brings students’ low ability to make scientific arguments. This study had compared the effect of the strategies of jigsaw, two-stay-two-stray (TSTS), and discovery-learning (DL) in promoting Indonesian secondary school student’s argumentation skills in the concept of chemistry reaction-rate. Data were collected using open-ended tests and video observations. The results of quantitative analysis show that jigsaw and TSTS were more effective than DL in enabling the students to produce high quality arguments. The results of observation data analysis show that distinctive learning experiences the students had in the form of chance to conduct diverse types of discussion under reasonable time allocation caused the differences of effect between the strategies. This finding suggests that implementing an argument-driven learning strategy that provides students with fruitful opportunities to perform intense debates is highly recommended to promote students’ skills in scientific argumentation.
Amine-Modified Silica (AMS) and Quaternary Amine-Modified Silica (QAMS) has been synthesized through the sol-gel process for adsorption Au(III) in aqueous solution. The aim of this work was to compare the effect of addition three methyl group of AMS to form QAMS on its character, thermodynamics and kinetics parameter of sorption of Au(III) in aqueous solution. Characterizations performed by FT-IR, XRD, SEM and BET analyzer. Sorption study was carried out in a batch system under the various experimental conditions including the effect of medium acidity, a variation of Au(III) concentration (thermodynamics study), and variation of contact time (kinetics study). Optimum pH of sorption Au(III) on AMS was 3 and shift into 5 on QAMS. Thermodynamics sorption study by Langmuir isotherm models indicates that there was an increase of sorption capacity from 37.94 mg/g (AMS) to 74.47 mg/g (QAMS). Kinetics sorption studies by Lagergren, Ho, and RBS models indicate that the sorption Au(III) in this research fitted well with the RBS models. The addition of 3 methyl group also increased the sorption rate of Au(III) on QAMS (ka = 77.29 min-1 (mole/L)-1) over AMS (ka = 69.22 min-1 (mole/L)-1) and reinforce the electrostatic interaction between active site of QAMS.
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