Table of contents

The 1^st International Conference of Chemistry (ICCHEM)

Yogyakarta, Indonesia

28-30 September 2018

List of Editors are available in this pdf.

PREFACE

The International Conference of Chemistry (ICCHEM) is an annual conference organized by Department of Chemistry Education, Faculty of Mathematics and Natural Sciences, Universitas Negeri Yogyakarta, Yogyakarta, Indonesia and successfully held from 28 to 30 September, 2018. The theme of the 1^st ICCHEM is optimizing and empowering chemistry for sustainable development of science and technology. The conference was a forum for researchers, educators, students, policy makers, and practitioner to achieve the innovation and social development through research and education on chemistry, as it is accentuated by the theme of this conference. The scope of this Conference covers the area of chemistry and chemistry education. This proceeding contains 34 papers that have been carefully peer-reviewed and selected from 65 papers submitted to the conference.

We would like to express our gratitude to the reviewers of these manuscripts, who provided constructive criticism and stimulated comments and suggestions to the authors. We are extremely grateful as organizers, technical program committee and editors and extend our most sincere thanks to all the participants of the conference for their fruitful work and their excellent contribution to the development of this conference proceedings. Our sincere gratitude also goes to the IOP Publishing editors and managers for their helpful cooperation during the preparation of the proceedings.

On behalf of the Organizing Committee of the 1^st ICCHEM

Assoc. Prof. Dr. Retno Arianingrum

List of Committees are available in this pdf.

All papers published in this volume of Journal of Physics: Conference Series have been peer reviewed through processes administered by the proceedings Editors. Reviews were conducted by expert referees to the professional and scientific standards expected of a proceedings journal published by IOP Publishing.

The leaves of Screw-pine (Pandanusodorifer) which contain natural cellulose were used as sources of carbon to prepare activated carbon. Contained 28-30% of water, the leaves were dried for 3-5 days by sunlight. The pyrolysis process of dry leaves yielded 25.7% of carbon that was then followed by grounding and sifting steps to 80 mesh of particle size. This uniform particles were mixed with 5% HNO₃ activator in batch system for 24 hours. Physical activation conducted at 700°C and obtained 70.8% activated carbon. The characteristics of activated carbon were compared to the carbon base by using porosimeter, referencing to SNI 06-3730-1995 and finding the adsorption isotherm patterns. Activated carbon surface area was 337.9 m²/g that is classified as micro-pore substance. In accordance to SNI requirements, the activated carbon fulfilled water content, ash content and adsorption capacity of I₂ while the study of efficiency adsorption is satisfy at 92.5436%, 97.5707%, 97.9811% and 96.2066% of Cd, Cu, Zn and Fe respectively.

The aim of this study was to prepare and characterize a potential adsorbent based on zeolite from Klaten, Central Java, Indonesia. The pre-treatment of natural zeolite (ZA) consists of chemical activation using HCl (ZAA) and NaCl (ZAT). Cationic surfactant benzalkonium chloride was used for modification of the zeolitic surface. ZA, ZAA, ZAT, and modified zeolites were characterized by FTIR, XRD, and AAS. The cation exchange capacity (CEC) of the natural zeolite measured by 1 M NH₄OAc method. Results show that the higher Si/Al ratio was achieved when natural zeolite was activated by the strong acid of HCl, but acid activation did not change the structure of the zeolite itself. The result of XRD analysis supports the AAS analysis result in which the degrees of crystallinity of zeolite increased after acid activation. The studies by FTIR and XRD analysis indicated that the zeolite structure remained unchanged after the modification with the cationic surfactant. Thus the activated and modified zeolites create a new material adsorbent to reduce pollutants in the environment.

A sulphuric acid-crosslinked chitosan/PEC film had been synthesized and applied for adsorption of HA from aqueous solution. The parameters for adsorption study were an optimum ratio of chitosan/pectin composition, contact time, the effect of the solution pH, and HA concentration. The model for adsorption kinetics and isotherm adsorption as well as desorption study were also conducted. The result showed that the film was durable in water at pH 2 to 12. The analysis using FTIR indicated a shift of absorption peak at 1527 cm⁻¹ (bending vibration N−H in −NH₃⁺). Analysis with SEM showed the morphological differences of the film before and after adsorption and after desorption. Adsorption reached its optimum capacity in the film with a ratio of chitosan and pectin composition 70:30, at pH 6, contact time of 480 mins and HA concentration of 450 mg L⁻¹. The kinetic model of HA adsorption could be explained by the second-order kinetic model of Ho & McKay and the adsorption isotherm follows the Langmuir isotherm model with a maximum adsorption capacity of 50.0 mg g⁻¹, the Langmuir constant (K_L) of 1.49×10⁵ L mol⁻¹ and the adsorption energy was found to be 29.7 kJ mol⁻¹. The highest desorption was 82.5% using 1 M NaOH.

This study aims to determine the effect of combustion temperatures and copper(II) oxide concentrations on ceramic glaze color. Electrocoagulation process was carried out using optimum conditions: pH 8, electrocoagulation time of 120 minutes, Al-Fe electrodes, and current density of 1.25 mA/cm². Experiment variables include combustion temperatures (999, 1060, 1101 °C) and copper(II) oxide concentrations (0.88; 1.76, 2.64, 3.53% ). The results of the coagulant characterization with XRF showed copper(II) content of (22.04 ± 0.73)%. Besides that it also contains of other metals such as Cr, Cd, and Pb however below the detection limit. Coagulant is a metal hydroxide which is dried and calcined formed the oxide. Then, it was applied as a glaze ceramic dye. Based on the analysis of homogeneity using chromameter, the brightness value (L*) increased at the combustion temperature of 999 and 1060 °C, but at a temperature of 1101 °C it decreased. The green color value (a*) decreases when the combustion temperature is raised but the yellow value (b*) increased. When the metal oxide concentration was increased, L* and a* values decreased. While the b* value increased at a concentration of 0.88 to 1.76%, but at a concentration of 2.64 to 3.53% decreased.

This research aims to characterize activated NaOH carbon of sea pandanus leaves (P. odorifer) which include water content, ash content, volatile content, carbon content and adsorption capacity of iodine. Further, we investigate adsorption capacity of activated NaOH carbon to Fe³⁺ and Cu²⁺ ions, and its adsorption type. Sea pandanus leaves (P. odorifer) was taken from Trisik Beach in Kulonprogo. The carbonation process is carried out at a temperature of 500 °C, followed by chemical activation using 1% NaOH solution and physical activation with a temperature of 700 °C while carbon dioxide gas flowed for 2 hours. Identification of capacity of activated carbon to heavy metals is conducted in batch. The characterization results show that water content and iodine adsorption capacity of activated NaOH carbon complied with SNI 06-3730-1995, respectively of 5.38% and 2463.63 mg/g. While the volatile content (59.09%), ash content (17.88%), carbon content (17.66%) did not fulfill SNI 06-3730-1995. The adsorption capacity of activated NaOH carbon to heavy metal ions of Fe³⁺ and Cu²⁺ respectively is 0.895 and 0.996 mg/g.

Research has been conducted to determine the chemical and physical characteristics of Yeast Hydrolysis Enzymatic (YHE) based on its fermentation media. The fermentation medium used is white, red, and black rice. The procedures carried out include the sample preparation, the fermentation, making pineapple crude and the enzymatic hydrolysis stage. In this study measured Cr³⁺ content using voltammetry method, and measurement of protein content using Kjehdahl method. There are three kind of YHE: YHE from yeast which is grown in white rice (YHE-Er), red rice (YHE-Rr) and black rice (YHE-Br). YHE from yeast grown in various growth media has different Cr³⁺ content. The lowest yield of Cr³⁺ was YHE-Wr which was 32 × 10⁻⁵% while YHE-Br was 37 × 10⁻⁵% and YHE-Br was 40 × 10⁻⁵ %. The protein content of YHE-Wr, YHE-Rr and YHE-Br were respectively 38.45; 38.48; and 39.23%.

Iron(II) has been known to exist as high-spin (⁵T₂) and low-spin (¹A₁) states. The first and the second states are due to the weak and strong ligand fields of the corresponding complexes, respectively. The magnetic moments of the two states are then immediately distinguished, being about 4.9-5.4 BM due to four unpaired electrons, but 0-0.6 BM due to no unpaired electrons in the corresponding electronic configuration of 3d⁶ system for the former and the latter, respectively. It could be reasonably understood that in the "middle" ligand field strength the magnetic moment may no longer reflect neither fully high-spin nor fully low-spin but to be in between the two, and thus in this situation the concentration of the two fractions may be induced by temperature or pressure. Thus, the term spin-state transition or spin crossover in iron(II) or spin equilibium of ¹A₁ ⇋ ⁵T₂ are then introduced. Indeed, many complexes of [FeN6]²⁺ were found to be temperature dependence associated with the spin-state transition. In this paper, the iron(II) complexes of six N-coordinating agent of five-six membered rings and its character of magnetism, Mössbauer and UV-Vis electronic spectra as well as bond lengths are discussed.

The nanosilica was prepared from bamboo leaves ash by calcination method in 800°C for an hour. The result was 350 g silica from 500 g of its ash. The SEM shows a homogeneous surface of SiO₂ and the EDX consists of 56,73% Si. The FTIR test indicates the Si-O-Si functional groups. The XRD shows 2θ = 21,6 which corresponds to JCPDS No. 39-1425 and 18-1170. The supplement was vitamin C tablet which prepared into slow release supplement model, by mixing of three component : generic ascorbic acid, magnesium stearate, and nanosilica in certain composition. Some assessments were carried out to determine the tablet's characteristic: the size, homogeneity, and hardness. Physical testing of the slow-release vitamin C tablet was found to meet the requirements of tablet by Indonesian Farmakope. In vitro assessment was represented by dissolution test in simulation solutions of stomach by 0,1M HCl and the intestine by citric acid. The result showed that the dissolution of the samples were slower than the control tablets. This indicates that the addition of silica-nanoparticles affect the characteristics of slow release supplement.

Oil and gas industry exploration activities produce a lot of formation water called produced water with a total of up to millions of barrels per day. Produced water from oil fields has different chemical compositions depending on geographic location, formation depth, oil production methods, and age of oil production wells. Currently, produced water is still considered as industrial waste water containing heavy metals which are harmful to humans and the environment, and require special treatment to be able to dispose of it into the environment. To determine heavy metals content in produced water of oilfield exploration, laboratory tests were performed for Siak Regency of Riau Province. Laboratory testing parameters include arsen, barium, boron, cadmium, cobalt, chromium hexavalent, iron, copper, lead, manganese, selenium, mercury, and zinc using instrument inductively couple plasma (ICP-OES) Perkin Elmer 8300DV, spectrophotometer HACH DR2800, and LUMEX RA-915. The results show the heavy metal content of <0,01 − 1,0 mg/L, and only barium and boron have a concentration of more than 1.0 mg/l. Without advance treatment especially to eliminate heavy metal content, the produced water in Siak Regency is harmful as source of drinking water and other daily activity including for fisheri and crop plantation.

Metallophthalocyanine (MPc) complexes based on abundant transition metals has greatly interest as catalyst due to their attractive features including a rich redox behaviour, the potential to bind with metals or non-metals in the central cavity. Among the transiton metal, cobalt complexes as electrocatalyst are preferable due to their efficient catalytic activity. Immobilisation of the catalyst onto surface may improve with the poly 4-vinylpyridine (P4VP) as polymer backbone. However, aggreagation of MPc is the challenge to overcome. This study aims to investigate the interaction behaviour of cobalt(II) hexadecfluorophthalocyanine (CoPcF₁₆) within poly 4-inylpyridine (P4VP) using UV/Vis spectroscopy. Two solutions of CoPcF₁₆ and P4VP were mixed and the interaction of CoPcF₁₆-P4VP was observed through the time using UV/Vis spectroscopy at wavelength 500 to 750 nm. The outcome suggests that coordination of the electrocatalysts is favoured by the comportment of a high concentration of 4VP. Subsequently, this CoPcF₁₆-P4VP electrocatalyst has a potential for water splitting or hydrogen evolution.

The aim of the study was to identify the content of total phenolic and flavonoids, and to test the antioxidant activity of leaves extract of Dendrophthoe falcata hemiparasite on Melia azedarach plants. The research method was carried out by extracting dry powder from the leaves of D. falcata with ethanol. Ethanol extract was partitioned using consecutive n-hexane, chloroform, and ethyl acetate solvents. Each fraction was then analyzed for the content of total phenolic and total flavonoids by spectroscopic methods. The method for testing antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl (DPPH) by in vitro. The results showed that leaves of D. falcata were rich in phenolic compounds and flavonoid. Furthermore, in the antioxidant test showed ethyl acetate fraction had the highest activity, with IC₅₀ 6.66 ± 0.11 μg/ml. This study shows that D. falcata leaves have potential as natural antioxidants.

The human body mostly (more than 80%) consists of liquid, so that the metabolic processes in the human body involve the interaction between solvents and solutes in both ionic and compounds. Metal mercury is a toxic metal, can cause poisoning. The hydration of mercury ions is observed by performing molecular dynamics simulations of molecular mechanics. The base set used is DEF2-ECP for Hg atoms, while for water molecules used dunning DZP base collection. Simulation is done using potential partners and potential 3 bodies. The simulation is done by mixing 1 Hg²⁺ ion mixed with 499 H₂O molecules. The simulation results in the form of trajectory data are further processed to determine the structure and dynamics. Based on RDF analysis shows that the average Hg and O (water) atoms are 2.22 A. Based on CND analysis, it is known that the coordination numbers of hydration of Hg in water are as much as 6 molecules of water. Thus it is known that the hydration of Hg ions in water forms a distorted octahedral molecule structure. Ligand (water) residence time in Hg based on molecular dynamics analysis shows that hydration of Hg with water is stable.

Liquid fuels from polypropylene plastic waste and co-reactants biodiesel from Waste Cooking Oil have been successfully performed by catalytic cracking method. The catalyst used is Al-MCM-41: Ceramics with ratio 7:3. The catalyst was characterized by XRD, SEM, Pyridine-FTIR, N₂-Adsorption-Desorption, and the product of catalytic cracking were investigated by GC-MS. The Liquid fuels obtained was mixed with commercial fuels and MTBE with ratio (10:87.5:2.5). The results showed liquid fuels have the largest percentage of gasoline (C₇-C₁₂) are 93.92 fraction produced. The performance of liquid fuels is enhanced with the additive MTBE investigated by generator set engine with gasoline-based fuel. The liquid fuel blends on the CB50 feedstock variation has the highest percentage of thermal efficiency of 27.42%, with a density value of 722.55 Kg/m³, a flash point of -5.9 ° C, a viscosity of 0.238 cst, and a heating value of 15,465, 94 Kcal/Kg. Characteristics of liquid fuel blends (CB) manufactured in accordance with SNI 06-3506-1994. Addition of the MTBE additive enhances the performance of CB100 mixture by 0.74% to the variation of TCB100 and 4.66% to Premium RON 88 at maximum loading of 2090 Watt. Characteristic of liquid fuels produced were also suitable with commercial gasoline standard.

In this approach, chitosan thin films have been prepared using single and multiple dip coating method. The glass substrates was heated 100 °C as a pre-treatment and the fabricated thin film were post heated in various temperature: 100 °C, 210 °C, 220 °C and the effect of pre and post heat treatment on their wetting, structural and morphological properties has been investigated. Scanning electron microscopy (SEM and contact angle measurement have been applied for the characterization and study of thin film surfaces. The results of SEM exhibit the aggregation and formation of chitosan films on the surface of substrate changed through applying heat pre-treatment substrates and increasing of heat post temperature to the chitosan surface.Wettability studies showed that the contact angle of prepared thin films was influenced by various parameters such as heat pre-treatment on glass substrates, variation of heat post-treatment and surface morphology.

This study focused on the development and validation of the chemistry module in food additive topic for vocational students in the tourism field. An exploratory mixed method was conducted with four steps include qualitative, development, quantitative and interpretation. The Food Additives Module (FAM) was developed based on the basic competence of food processing and extended on chemistry content. To get the content and face validity, two experts had reviewed the FAM and gave the feedback to revise it. The analysis of FAM feasibility gained by the response of 7 chemistry teachers on four aspects includes the worthiness of chemistry concept, concept presentation, linguistics, and graphic. This study had produced the FAM module based on the contextual approach. The module had four theme namely sweeteners, preservatives, coloring and flavoring foods. A group of experts declared that the FAM was worthy as the chemistry enrichment content for vocational students of tourism field. The teacher gave a good response to the FAM quality. This study suggests that the FAM will be a useful tool for teachers to improve the chemical literacy of students in vocational tourism school.

The study were aimed to compare the integrated thinking in the form of science process skills and analytical thinking ability; and student learning activities toward chemistry learning of eleventh grade who learned using the 7E learning cycle and expository model. The quasi experimental model with post-test only design was used as an research design. To achieve this goal, sixty students were randomly selected from one public senior high school in Bantul regency, Yogyakarta Province, Indonesia then divided into two groups- there are 28 students of the experimental group which was taught by using the 7E learning cycle and 32 students of the control group which was taught by the expository model. Data were collected using the following two instruments: 5-item integrated thinking ability test, and 29 questionnaire statements of students activity. To answer the questions, Multivariate Analysis of Variance (MANOVA) was used. The results showed that students who learned using 7E learning cycle and the expository model had statistical differences in integrated thinking ability and activities towards chemistry learning at 0.05 level of significance; the students who learned using the 7E learning cycle showed more integrated thinking ability than did the students who learned using the expository model; also the result and indicated than student activities higher than did the students who learned using the expository model. It can be concluded that 7E learning cycle model can be used to improve integrated thinking ability and students' activities. The researcher recommends that more studies should be conducted about the effect of this model on other instructional variables.

This study investigates the effect of Chemoentrepreneurship Oriented Inquiry Module (COIM) a colloid topic to enhance students creativity in teaching chemistry subject. The work was quasi-experimental, including pretest-posttest control group design. The used instrument is in the form of a description test, specially designed to determine the creativity of students. The results showed the use of COIM was effective as proven by 1) increase in student creativity index from 60 to 79, and 2) N-Gain level of attainment was in the range of 0.5 with a medium category. Overall, concluded that the use of Chemoentrepreneurship Oriented Inquiry Module effectively can enhance. Introduction The colloid is one of the learning topics in basic chemistry courses that are very important to be taught to students because it is a highly contextual topic. Sub-chapters in the colloid topic include dispersion systems, types of colloids, colloid properties and the application of colloids in everyday life.

The aims of this study was to investigate the effect of discovery learning model on students' integrated thinking abilities in the form of analytical thinking skills and science process skills, and students' creative attitudes in the buffer solution lesson. The population was students of eleventh grade students of science class in Yogyakarta, academic year of 2017/2018. The sample of this study consisted of two classes in Yogyakarta public high school taken using a random sampling technique. Each experimental and control class was 32 students. The treatments for experimental class was the use of discovery learning, and expository model for the treatment on control class. Data collection used in this study was an integrated thinking ability test and students' creative attitudes questionnaire. The data of students' integrated abilities and creative attitudes were analyzed by observing the results of significance value and partial eta squared on MANOVA test. The results of multivariate analysis showed that there was an effect of discovery learning on students' integrated thinking abilities and creative attitudes of 12%. This means the integrated thinking abilities and creative attitude of students applying discovery model is better than integrated thinking abilities and creative attitudes of students with expository model.

Many students assume that the chemistry subject is difficult. We create a Testlet Aassessment Instrument (TAI) as a diagnostic tool that can be used to detect students' level of difficulty in learning chemistry. Hence, this study aims to analyze the computer-assisted TAI to measure students' learning difficulties in the chemical bond subject matter for class X students of the senior high school in Madiun of East Java Indonesia. This study used descriptive-quantitative analysis methods and15 students from 3 different schools as participants. The computer-assisted TAI consists of 10-question stems, that's stem 1 until stem 10. The result showed that for stem 8 only 4% students can answer correctly and thus the stem is considered the most difficult. Scoring of the TAI used graded scoring with 4 categories. The implication for applying the computer-assisted TAI for measuring students' difficulties in chemical bonding subject was discussed.

Technology-based learning was always done to face up the growth of technology in the modern era. It attracted students to understand the subject matter. The development of the technology-based practicum media could facilitate students in practicum without the real tools and materials. The media could save the tools and materials that were expensive. However, need analysis were required to find out what it needed in the chemistry class according to the chemistry teachers. This research is descriptive research with quantitative and qualitative data. This need analysis used a questionnaire as an instrument that contain 6 open-ended questions and 2 yes-no questions. A virtual laboratory is one of the practicum media that can resolve the limitation of tools, materials and learning time. Respondents from this research were 37 chemistry teachers who have been teaching chemistry for at least 5 years. The data were analyzed using analysis of percentages. The results of this study obtained 91.89% of respondents stated to need an integrated virtual chemistry laboratory in hybrid learning. While practicum-based matters that were perceived to require a virtual chemistry laboratory were chemical equilibrium, electrochemistry and reaction rates. This research can be used as a criterion for developing the technology-based media.

This study aims to analyze the characteristic, feasibility, teachers' and students' responses of Hydrocarbon Chemistry and Petroleum (HCP) module based on the context of vehicle case on automotive engineering. Exploratory mixed method has been employed in this research. The research procedures used four steps including qualitative, development, quantitative, and interpretation step. The instruments used to collect the data consisting the three questionnaires, one open questionnaire to obtain the validation and two close questionnaires to collect the teachers and students' responses toward the HCP module. HCP module based on the context of vehicle case on automotive engineering program was yielded as a result of this reseach. The characteristic of research product was integrating between chemistry and automotive subject based on basic competence of curriculum and integrated by vehicle context in first chapter, concept map, activities, examples, and exercise. A group of experts consisting two lectures were confirmed that the HCP module has a correct chemistry content. A very good category was given as the response of the teacher. Moreover, the students response were very interest toward the HCP module. The students and the tachers could be utilize the HCP module as learning sources reference to gain a succesfull chemistry learning.

This study investigated the impact of student-initiated green chemistry experiments on their level of knowledge, awareness and practices of environmental sustainability; and on their achievement in the topic of rate of reaction. The quasi-experimental study involved 46 secondary school students with 23 students each in control and treatment groups. A set of questionnaire and a set of test were employed in the study; and data was analysed using descriptive and inferential statistical techniques. Results showed significant difference in awareness, between the groups; but a weak insignificant correlation between knowledge and awareness on green chemistry. It was also indicated awareness on green chemistry as a strong significant predictor for practice. However, results revealed no significant difference in the achievement between students undergoing traditional chemistry experiments and the green chemistry experiments. Nevertheless, students participated in designing green chemistry experiments have higher level of awareness and practice of environmental sustainability. This study recommends that teachers should empower students with suitable mechanisms to address sustainable environment issues in classroom or laboratory instruction to promote sustainable practices among them.

The research purposed to analyze the characteristics of chemistry module on acid-base and electrochemistry topic based on vehicle context, to analyze the feasibility of module according to chemistry learning experts and to analyze the response of chemistry teachers and students of Automotive Engineering Program (AEP) about this module. This research using mixed methods and exploratory model design. The data collected from expert validation sheets also teachers and students response questionnaire. Technique of data analysis begins by converting qualitative data into quantitative data using Likert scales. Furthermore, the total and average score of each component can be determined from the quantitative data. The result of the average scores were converted into qualitative feasibility criteria according to the rating category. The product of the development was a chemistry module on acid-base and electrochemistry topic based on vehicle context for students in AEP. The experts considered feasibility of the module. This module had assessed by 5 teachers and 10 students. The module assessed by teachers showed a very good response while the module assessed by students showed a good response. Therefore, this module is feasible and can be used as a learning resource for students of AEP to enhance quality of chemistry learning.

This study aimed to analyze the suitability of materials teaching with aspects found in the scientific approach, and the steps of problem solving model. The sample of this research was three textbook materials of class XI chemistry. It was used by some high schools in Klaten Regency. The analysis was conducted on three teaching materials that were coded X, Y, and Z. The result of the research showed that the compatibility toward the scientific approach of textbook X and Y was sufficient category, textbook Z was very poor category. Conformity to problem solving model step sample X was poor category, sample Y was sufficient category, and sample Z was very poor category. These chemistry book materials which used in the high school should be added according to aspects of the scientific approach and problem solving steps that have not been listed.

The aim of this research is to identify the effect of guided inquiry on students' activities and communication skill in chemistry. The population was all eleventh grade high school students in SMAN 2 Wates. The samples of this study were obtained by using random sampling technique. The samples consist 48 students, with 21 students in class XI MIPA 2 as an experimental group and. 27 students in class XI MIPA 4 as control group. While the students of experimental group were taught using guided inquiry and the students of control group were taught using expository learning. Data of this research were collected by using questionnaire and observation for students' activities and communication skill. The data were analyzed by using Multivariate Analysis of Variance (MANOVA) test whereas the significant level used was 0,05. The results show that there were significant differences between students who were taught using guided inquiry and students who were taught using expository. This study demonstrates that guided inquiry is significantly more effective to improving student's activity and communication skill than the expository learning which are usually applied by teachers in class.

This study aims to determine students scientific literacy skills after learning with a contextual-flipped classroom model. In flipped classroom-contextual learning, students study the lesson material through contextual videos outside the classroom, then conduct discussions in class and lab work. This study used a qualitative method with 36 students in class XI at senior high school in Jakarta. Data collection were carried out through scientific literacy tests, observation, interviews, and reflective journal of students. The students' scientific literacy skills in this study refer to the scientific literacy of PISA. The results showed that 16.7% students had achieved scientific literacy at level 6; 38.9% at level 5; 11.1% at level 4; 27.8% at level 3; 5.6% at level 2 and 1. In addition, the results of the study show that aspects of scientific literacy have also been mastered by students. Mastery of scientific literacy aspects, concerning: aspect of the scientific context is 83.92%, aspect of science knowledge is 84.36%, and aspect of scientific competence is 84.06%. Thus, it can be concluded that acid-base learning with a contextual-flipped classroom model can improve students scientific literacy skills.

Scientific literacy and scientific attitudes are two conceptual foundations for students that have to be increased in both developing and developed countries. This research aims to identifythe effect of science-technology-society (STS) model on scientific literacy and scientific attitude of students on the subject of buffer solution. This research was quasi-experimental research using nonequivalent control group design. The sample was determined by cluster random sampling technique. The sample of this study was two classes. One class as an experimental class consisted of 34 students which used STS model. Other class as a control class consisted of 33 students which used direct instruction model. The data analysis used the manova test at the significance level of 5%. The results of the study showed that there was significant effect of STS model on scientific literacy and scientific attitude of students on the subject of buffer solution.

A laboratory has a very important role in learning chemistry. It facilitates the experimental activity which supports the students' understanding. The development of information and communication technology has provided an innovation known as the virtual laboratory. This study aims to reveal the quality of virtual chemistry laboratory (virtual chem-lab) integrated into hybrid learning on chemical bonding. This research was a research and development study. The development procedure used in this study consisted of four stages: analyzing, product planning, product developing, and product assessing being adapted from the ADDIE (Analysis, Design, Development, Implementation, and Evaluation) development model. The initial product of the virtual chem-lab was content validated by material and media experts. Product assessment was applied to 28 chemistry teachers, including content, learning quality, and technical quality aspects. The result of this assessment was descriptively analyzed to reveal the quality of the product. The findings of this study reveal that the quality of the virtual chem-lab integrated hybrid learning is in a good category. Thus, the virtual chem-lab is potentially used for further teaching-learning.

The objective of this research is to test the effect of using jigsaw puzzles towards students' understanding in writing the chemical formulas of ionic compounds. This quasi-experimental case study design research involves 115 science stream students from two secondary schools in Larut, Matang and Selama district. Achievement test is used to measure students' understanding in writing the chemical formula of ionic compounds. A survey is also conducted on the experimental students' perception on the activity using questionnaires. Descriptive and inferential statistics are used to analyse the data, with the assistance of the Statistical Package for Social Sciences (SPPS) software. The findings proved that the jigsaw puzzles are effective in assisting students to write the chemical formula of ionic compounds. Students also have a positive perception towards the usage of jigsaw puzzles in teaching and learning activity. As conclusion, this jigsaw puzzle activity should be implemented in teaching and learning to assist the students in writing the chemical formula of ionic compounds. This study implies that the elements of game should be infused during the planning of teaching and learning to ensure that learning is more heuristic.

This research aims to find out the effect of scientific approach based jigsaw model on self-efficacy and achievement of tenth grade high school student on redox reaction material. This research was a quasy experimental using post-test only design. This study involved 120 tenth grade high school students in Yogyakarta regency, Indonesia. A total of these samples classified into two classes, the experimental class using scientific based Jigsaw model and control class using direct instruction. Data collection in this study used questionnaire to collect students'–self-efficacy and test on redox topic to collect students' achievement data. Data analysis techniques in this study using Multivariate Analysis of Variance (MANOVA) to examine the effect of scientific based jigsaw model on students' self-efficacy and achievement among the experimental and control classes. The results showed that s there was significant effect of scientific based jigsaw model on students' self-efficacy and cognitive achievement. Hence, the teachers are expected to apply scientific based jigsaw model to the chemistry learning because it can increase student self-efficacy that has implications for improving students cognitive achievement.

This research was conducted to analyze the effect of using virtual chemistry laboratory integrated hybrid learning toward students' learning achievement on the subject of thermochemistry. Thus, the research was set as a quasi-experiment research using posttest and non-equivalent control group design. By purpossive sampling technique, the samples from 3 classes composed of 1 public senior high school were selected. The classes were divided into experiment class (EG) using both virtual chemistry laboratory integrated hybrid learning and traditional hands-on laboratory, control class 1 (CG-1) using virtual chemistry laboratory integrated hybrid learning only, and control class 2 (CG-2) using traditional hands-on laboratory only. The corresponding data were collected on the basis of a multiple choice test of chemistry learning achievement. The data were then tested by Anova. The results show that there is a significantly different in students' learning achievement among the three classes EG, CG-1 and CG-2.

The paper portrays the second year report of a three-year longitudinal study of ethnochemistry integration in Culturally Responsive Transformative Teaching (CRTT) teaching model in secondary schools. The CRTT develop based on Culturally Responsive Teaching (CRT) as an approach that includes students' characteristics and cultural references in all aspects of learning and transformative learning framework. The study developed CRTT teaching model in the first year of study and consists of five phases of self-identification, cultural understanding, collaboration, critical reflections, and transformative construction. The qualitative methodology approach has been employed with observation, interviews, and reflective journals as data collection. The CRTT teaching model was implemented in chemistry classrooms from two secondary schools. The study involved 68 students of year-10 in the topic of electrolyte and non-electrolyte solution. The data was analyzed from the basic principles of cultural identity category. The results showed that the integration of ethnochemistry in CRTT teaching model has engaged students in empowerment their cultural identity and nationalism, cultural differences awareness, and learning identity development. The teaching model is also relevant to the policy of national curricula of nationalism in relation to character and culture identity development.

This paper describes a second year of two-year of longitudinal study of the integration of Science, Technology, Engineering, Art, and Mathematics (STEAM) in chemistry learning in secondary schools in which the importance of critical and creative thinking skills were explored. The study involved 76 students of Year 11 from two secondary schools in Indonesia. The STEAM integration was implemented in the teaching of acid and base through a project-based learning model. The research employed a qualitative approach to explore the integration of STEAM in chemistry, students' critical and creative thinking skills development. Data were collected through observations, interviews, reflective journals, critical and creative thinking skills assessment. The students develop their STEAM projects by integrating chemistry concepts with STEAM principles. The study results were analyzed based on the pattern themes found in different data sources. It showed that students developed creativity and critical thinking skills. The study faced challenges of STEAM integration with chemistry concepts, empowering teachers, engaging students, and managing time and resources. The integration of STEAM provided the opportunities for students in chemistry learning engagement and several areas of thinking skills development in relation to the current curricula objectives.

The aim of the study was to determine the effect of using a virtual chemistry laboratory on students' cognitive learning achievement. The study sample was 163 eleventh grade students from two high school in Cilacap regency, Central Java, Indonesia and selected randomly. The research sample was divided into three groups, where each group had different learning activities. Learning activities in the CG were chemistry learning with the practicum in the traditional laboratory, EG-1 were chemistry learning with the practicum in the virtual chemistry laboratory, and EG-2 were chemistry learning with the practicum in traditional laboratory and virtual chemistry laboratory. The data were collected by multiple-choice test questions with 30 items and analyzed using ANOVA (Analysis of Variance). The result showed that the cognitive learning achievement of students in the EG was higher than the CG. This result indicates that there is an effect of using virtual chemistry laboratory on student's cognitive learning achievement. This result of the study can be used as a reference for chemical educators to be more creative and innovative in providing facilities to support the achievement of cognitive learning achievement.