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Varied initial concepts can be an obstacle or support in understanding a new concept. The study of changes in students' chemical concepts was carried out on thermochemical material. This study aimed to examine changes in students' thermochemical concepts in each subject of high, medium, and low ability. Qualitative descriptive research with mixed methods was conducted on SMAN 1 Bumi Raya Morowali, Central Sulawesi students. The study began by giving an initial test to all students of class XI IPA 1 and 2, as many as 60 students, to obtain initial concept data and the basis for grouping subjects on each ability criterion (high, medium, and low). Every two people from each ability group in semi-structured interviews. Thermochemical material is re-taught using a metacognitive skill learning model and given a final test and interview to get concept data after learning to assess conceptual changes. Five concepts become variables in this study: the heat of reaction, enthalpy of reaction in a calorimeter, Hess's law, energy diagrams, and bond energies. The results showed that concept changes occurred in all high, medium, and low ability subjects. Changes in students' conceptions occurred in the concepts of the heat of reaction, reaction enthalpy, calorimeter, Hess's law, energy diagrams, and bond energy. The most significant conceptual change occurred in the subject of medium ability and low ability, namely the concept of bond energy.

This study aimed to describe the improvement of learning outcomes by applying the learning model of Connecting, Organizing, Reflecting, Extending (CORE) with molymod-assisted hydrocarbon material of class X students of SMA Labschool UNTAD Palu. This type of research was experimental designs with one group pretest-posttest design. This study used 2 classes, namely class XA as replication class 1 (n = 26) and class XB as replication class 2 (n = 27). The students' learning outcomes were affective, psychomotor, and cognitive aspects. In replication class 1, the value of student learning outcomes was 71.37, while in replication class 2 was 66.00. The data analysis results showed increased student learning outcomes after using the Molymod-assisted CORE learning model in both classes. So it can be concluded that applying the Molymod-assisted CORE learning model on hydrocarbon materials can improve student learning outcomes for class X SMA LABSCHOOL UNTAD Palu.

This study aims to longitudinally describe the metacognitive skills and external representation in the context of problem-solving at Chemistry Education, Tadulako University. The qualitative study respondents were selected from a number of first year students for two consecutive semesters. Two respondents were selected based on results of selection using a metacognitive skills assessment questionnaire (MCAI) and we categorized as high and medium. Three problems were resolved by respondents at intervals of one to two weeks in each semester through a one-on-one thinking aloud and it was followed by a semi-structured interview. Data collection was recorded using a video camera. Metacognitive skills and external representation data from the odd and even semesters were deeply analyzed. This analysis technique was carried out by examining the results of problem solving and semi-structured interviews in detail and matching them with the indicators of metacogni-tive skills and external representation used by both respondents. The data analysis results showed that the thinking ability of respondents with high metacognitive skills in problem solving, experienced developments over time along with the development of their cognitive regulation and external representation. On the other hand, respondents with intermediate metacognitive skills during problem solving, were relatively the same for two consecutive semesters. Therefore, teachers need to consider the use of learning strategies by taking into account the number of students who have dominant characteristics in classroom learning, in terms of metacog-nitive skills and external representation.

This study aimed to describe the increase in understanding of students in class XI SMA 7 Palu on the buffer solution material after applying the discovery learning model. This type of research was pre-experiment with the design of one group pre-test-post-test. This study was conducted in two replication classes, namely, class XI MIA 1 as replication class 1 (n = 26) and class XI MIA as replication class 2 (n = 24). Testing of the data from research results data used descriptive statistical analysis of the understanding concept. The criteria for understanding the concept was good if the percentage of students who have the category of moderate, high, and very high is not less than 60%. The data results of analysis understanding of each concept obtained in the replication class 1. The concept of buffer, score 65. 38% increased to 96.15%. The concept of the properties of the buffer score 3.84% increased to 96.15%. The concept of acid-base buffer solution, score 0% increased to 92.3%. The concept of pH acid buffer, score 0% increased to 88.46%. The concept of pH base buffer, score 0% increased to 84.61%. In replication class 2, the concept of buffer solution score is 20.83%, increased to 91.66%. The concept of acid and base buffer solution, score 12.5% increased to 91.66%. The concept of pH base buffer, score 4.16% increased to 83.33%. The results of the analysis showed that there is an increase in understanding the good concept by applying the discovery learning model in the buffer material.

The research is purposed to describe the problem-solving ability of the Senior High School XI grader students in Palu city. The measurement of the problem-solving ability could be determined by solving the exercises of Hydrocarbon and Thermochemistry topics using the Polya’s sequences; consisting of understanding the problem, devising, doing the plan, and evaluating. The ability of students’ problem solving is classified well in every sequence in case of the number of high category students is 60%. The samples are 240 of 507 XI grade students learning chemistry in SMAN 3 and SMA Madani Terpadu in Palu City. The data of problem-solving is determined by providing a test in the form of a validated assay. The result shows the average of XI graders in Palu City only capable of solving the problem without understanding, devising, and evaluating while solving hydrocarbon topics. The ability is not even possessed by students in Thermochemistry. It implies that senior high school students in Palu could not represent the problem in the form of figure, symbol, statement, and mathematics statement or have not been able to devise the problem solving and correlate the obtained result with the related theory or concept. Therefore, the students should be trained to solve the problem in learning by application the problem-solving sequences.

This study aimed to obtain information about the differences in students’ learning outcomes through the implementation of a cooperative learning model of course review horay (CRH) type and think pair share (TPS) type on buffer topic in Grade XI Science at SMA Negeri 7 Palu. This study was pre-experimental with the static group pretest-posttest design. This study was conducted in two treatment classes those were class XI Science 2 as treatment 1 (n = 28) and class XI Science 1 as treatment 2 (n = 28). The research data were analyzed using t-test statistical two-party with prerequisites, normality, and homogeneity tests. The result of data analysis showed that the average learning outcomes of students in treatment class 1 (X̅1 value) is 78.82 with a standard deviation of 6.71, whereas for students in treatment class 2 (X̅2 value) is 74.25 with a standard deviation of 8.22. The result of the hypothesis test shows - ttable ≤ taccount + ttable which is -1.68 < 2.80 > +1.68 with a significant level (α) of 0.05 and degrees of freedom of 54. This means that H0 is rejected and H1 is accepted so it can be concluded that there is a difference in students’ learning outcomes using the cooperative learning model think pair share (TPS) type and cooperative learning model course review horay (CRH) type on buffer topic.

This study aimed to obtain a description of implementation on student’s learning outcomes the application of cooperative learning model of TGT based on demonstration Class XI on colloid material in SMA Negeri 7 Palu. The type of research used in this research was pre-experimental designs (non-designs) with research design that was one-group pre-test post-test design. Sampling in this study was chosen by purposive sampling. The sample consisted of two classes, class XI IPA 1 as experimental class 1 (n = 28) and class XI IPA 2 as experiment class 2 (n = 29). Student learning outcomes were processed using inferential statistical analysis of the Wilcoxon Rank-Unparpulated Ranking nonparametric test. The results showed that the experimental class 1 was Zcount (-4.62)

This research method was research and development (R & D), which purposed to obtain the sparkol videoscribe designs of colloidal material and the validity of designs that were reviewed by experts as theoretical experts. The object of this study was sparkol videoscribe. Data collection was divided into two, namely media design data and media validity that were designed by using assessment sheets from 5 experts, 3 people were the learning media experts and 2 people were the chemical material experts. Data were analyzed descriptively to determine the justification of the validity of the research object. The results of the data analysis obtained that sparkol videoscribe design of material colloid had characteristics, namely images, moving hand animation, music, explanation of material in the form of sound and the composition of sentences incorporated in whiteboard animation. The designs were declared valid with a very good category according to experts and can be used as a chemistry education media with a score of 3.7 based on the total score of the instructional media experts and 3.45 based on the total score of the chemical material experts.

Based on their ethnochemical expertise, the study intends to find the types, sections of plants, processing methods, and ways of use used to treat the liver ailment in the community of Balane village, Kinovaro District, Sigi Regency, Central Sulawesi. A qualitative research method was used, which included interview techniques. To treat liver disorders, the Balane community uses six distinct types of herbs. Cakar ayam (Selaginella doederleinii Hieron), daun sendok (Plantago major L.), jarong (Stachytarpheta indica (L.) Vahl), pegagan (Centella asiatica (L.) Urban.), sambiloto (Andrographis paniculate (Burm. F) Wallich), temulawak (Curcuma zanthorrhiza Roxb.). Plant parts that are used as medicine include herbs, leaves, rhizomes, and grains. Boiling is used to prepare the medicinal herbs, and the treatment is used for 1-3 months or until the patient notices a difference or recovers.

Utilization of pineapple is always focused on consumption for fresh fruit and animal feed. many people do not know the other benefits of pineapple. The presence of protease enzymes in it, increasing its utilization. The enzyme is bromelin, which can be obtained by isolating it from pineapple. For this reason, the aim of this study is to isolate the crude bromelain enzyme based on the maturity level of pineapple and then test its proteolytic activity. Pineapple was blended, then the filtrate was deposited, then centrifuged to obtain crude bromelain which is dried by the drying method and tested for its activity using milk substrate. The results showed that old pineapple is the best level of maturity and the sun is the best drying method with proteolytic activity of 0.053 and 0.056 MCU/mg respectively. Its optimum activity is pH 5.8 and 55 oC.

The objective of this study was to categorize and describe the behavior of chemistry education students' metacognitive skills who had a low chemical understanding (low ability) in solving problems. The findings would be the basis of data for the development of instructional design on chemistry topics by utilizing metacognitive skill aspects. The subject of this study was two first-year students of chemical education, academic year 2016/2017 that joined a basic chemistry course at the low-level ability in Universitas Tadulako. Two subjects were picked through networking using a valid test comprehension. The subjects were determined regarding the percentage of low ability which was 87% of 79 students. The profile data of metacognitive skill were obtained through an essay test, think aloud and interview. The earned data were reviewed, grouped, encoded, and examined to see its credibility employing the method and time triangulation. The research found that both students of chemistry education having a low-level of basic chemistry adopted planning skills in solving problems which were the problem identifying, goal determining, and strategy managing. However, both did not use monitoring and evaluating skills.

This research aims to examine the pattern of external representation and metacognitive skills in chemistry problem solving for students of chemistry education at Tadulako University. This picture will enrich the treasures of thinking skills in the field of science, namely how students/prospective teachers think in the context of metacognitive skills and how these students display an external representation system on chemistry concepts. The subject of this qualitative study was obtained through a purposive random sampling of 97 students who have been programmed Basic Chemistry course 2017/2018 academic year. Subjects were selected based on the results of the screening using a metacognitive skills assessment questionnaire (MCAI). Two problems solved by the subject by setting one-on-one thinking aloud. Subjects who complete the issue by setting further interviews at different times. The problem-solving activity was recorded using a video camera. The subject uses a type of representation and aspects of metacognitive skills and how to use the sequence of activities, analyzed in detail. The results showed that students of chemical education used metacognitive skills and external representations. So students solve chemical problems. Students also can improve knowledge retention related to linking new knowledge with previous knowledge, creating ideas, organizing, and even synthesizing knowledge. Students become productive and find solutions for problem-solving well

Penelitian ini bertujuan untuk mendapatkan kondisi optimum metanolisis minyak kelapa murni (MKM) dalam reaktor berpengaduk, metode pemurnian gliserol dan metode pemisahan metil ester asam lemak rantai sedang dari rantai panjang. Hasil penelitian menunjukkan MKM yang dihasilkan memenuhi persyaratan sebagai bahan baku metil ester asam lemak, sebab MKM yang dihasilkan mengandung air dan asam lemak bebas (FFA) mengandung asam laurat yang tinggi yaitu di atas 50% (52,86%). Kecepatan pengaduk dan waktu reaksi berpengaruh terhadap produksi 500 rpm dan waktu reaksi 50 menit. Pada kondisi tersebut fraksi massa metil ester asam lemak mencapai 100%. Metode pemurnian gliserol berpengaruh terhadap derajat kemurnian gliserol, dengan derajat kemurnian gliserol tertinggi adalah 98,04% yang diperoleh dari metode pemurnian ekstraksi dan netralisasi. Hasil fraksionasi metil ester asam lemak menghasilkan enam fraksi, tiga fraksi yaitu (fraksi I dan II dan VI) mengandung metil laurat yang lebih rendah dari MKM asalnya, dan tiga fraksi (fraksi III, IV dan fraksi V) mengandung metil laurat di atas MKM asalnya (di atas 70%). Fraksi VI dinyatakan sebagai metal ester asam lemak rantai panjang dengan rendemen 50% dari total metil ester asam lemak.