Jurnal Akademika Kimia
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Effectiveness of Google Classroom in Chemistry Learning on Stoichiometry Topic Viewed from Students’ Learning Motivation
Get PDFThis study aimed to determine the effectiveness of using google classroom in chemistry learning in terms of student learning motivation in MAN 2 Parigi, Sulawesi Tengah Indonesia. The sample in this study was students in class X MIA 2 (n = 23). The data analysis technique was the effect size d Cohen test, the value was 0.86 which had a very large effect category. This influence can be seen from students' learning motivation which increased with an average score of 3.70 which had a very good category. Based on these data it can be concluded that Google classroom affected the students’ learning results and learning motivation
The Implementation of Mind Mapping on Chemical Bond Learning Assisted by Information Technology towards the Students’ Learning Outcomes in Class X MIA 1 at SMA Negeri 1 Sindue
Get PDFThis study aimed to determine the influence of the implementation of mind mapping on learning of chemical bonding assisted with information technology toward learning outcomes of students in the Class X1 Science at SMA 1 Sindue. This study was a quasi-experiment with non-randomized pretest-posttest control group design. Sampling was based on special consideration (purposive sampling) with a sample of students of class X1 Science as the experimental class and class X2 Science as the control class. The instrument of this study was a test of learning outcomes. Data of the results was tested using statistical analysis of one-party t-test with prerequisite tests of normality and homogeneity tests. The data analysis obtained an average score of learning outcomes in the experimental class was 77.12 and in the control class was 67.6. Based on the hypothesis test with the t-test statistic of two parties obtained tcount of 10.89 and ttable of 1.95 at α 0.05. In this case, H1 was accepted and H0 was rejected because tcount was in the area of H0 rejection. This showed that there were differences in students’ learning outcomes through the implementation of mind mapping and conventional in learning of students in 10th grade at SMA 1 Sindue
Antioxidant Activity Test of Ethanol and Water Extracts of Celery (Apium graveolens L.)
Get PDFThis study aimed to determine the antioxidant activity of ethanol and water extracts of celery (Apium graveolens L.). Antioxidant activity test in this study used DPPH (2,2-diphenyl-1-picrylhydrazine) as a source of free radicals and vitamin C as a positive control. The antioxidant activity of celery extracts was analyzed using a UV-VIS spectrophotometer. Celery powder was extracted by firstly the maceration method using different solvents (ethanol and water) and secondly with the decoction method using water solvents. Celery extract was tested for antioxidant activity with various concentrations of 20, 40, 60, and 80 ppm. The results obtained that water extract (maceration) had a very strong antioxidant power with 23.713 ppm of IC50 values, for ethanol extract (maceration) had a strong antioxidant power with 59.492 ppm of IC50 value, water extract (dekok) had also a very strong antioxidant with 77.446 ppm of IC50 value, and vitamin C had a very strong antioxidant power with 15.631 ppm of an IC50 value. Based on the IC50 value obtained, the water extract by the maceration method was very good to be used as a source of natural antioxidants, because it had a very strong antioxidant activity value which was equivalent to vitamin C
The Effect of PQ4R (Preview, Question, Read, Reflect, Recite, Review) Learning Method with Internet-Assisted on Learning Outcomes of Students SMA Labschool UNTAD Palu on Salt Hydrolysis
No full textThis study aimed to describe the effect of PQ4R learning methods with internet-assisted on students’ learning outcomes of class XI SMA Labschool UNTAD Palu on salt hydrolysis material. The type of research was quasi-experimental with a nonrandomized pretest-posttest control group design. This study was conducted with two groups, namely the XI IPA class 1 as the experimental group (n = 21) and the XI IPA class 3 as a control group (n = 23). The testing of the research data used a two-party t-test statistical analysis. The results of data analysis obtained that the average of an experimental class was 63.19 with a standard deviation of 7.37 and a control class was 57.22 with a standard deviation of 8.19. The results of testing the hypothesis with the two-party t-test statistics obtained -ttable<tcount> +ttable (tcount 2.54 and ttable 1.68) with a significance level (α) = 0.05 and degrees of freedom (dk) = 35. Based on the results testing of the hypothesis, it can be concluded that H0 was rejected and H1 was accepted. This means that the PQ4R learning method with internet-assisted has a positive effect on the learning outcomes of students class XI SMA Labschool UNTAD Palu
Analysis of Nitrogen Nutrients in Liquid Organc Fertilizers from Wastewater of Rice Washing and Coconut Husks Mixture
No full textThis study aimed to determine the process of making a liquid organic fertilizer from wastewater of washing rice and coconut husks as well as to determine the amount of nitrogen contained in liquid organic fertilizer. Nitrogen contents were determined using a colorimeter. The results showed that the nutrient content of nitrogen in the liquid organic fertilizer from wastewater of washing rice and coconut husk from fermentation process in a sample of 10 days for a ratio of 1: 3, 1: 1 and 3: 1 was obtained that nitrogen contents were respectively 0.52, 0.41, and 0.20%. The results of fermentation in a sample of 14 days for a ratio of 1: 3, 1: 1 and 3: 1 obtained that nitrogen contents were 0.62, 0.49, and 0.25%
Oil Palm Empty Bunch Compost as a Source of Humic Acid
Get PDFHumic acid is a fraction of humic compounds that are part of soil organic matter. In this research, humic acid is extracted from oil palm empty fruit bunches compost. Compost is made from the process of counting the empty oil palm bunches, which are composted until the compost is cooked. The humic acid extraction process uses a strong base extraction method. The principle of humic acid extraction is to dissolve the humic compound with a base solution and then separate it by adding an acid solution (HCl solution). The extraction of humic acid from oil palm empty fruit bunches compost produced blackish-brown humic acid with a yield of 4.895%. The result showed that the main functional group content of palm oil empty fruit bunches compost humic acid was the -OH group and phenol group which had a conjugated carbonyl group and a more aliphatic humic acid structure. Quantitatively, the functional groups of humic acid functional groups each amounted to a total acidity of 7,400 cmol/kg, a carboxylic group of 520 cmol/kg, and a phenolic -OH group content of 6,880 cmol/kg. Research results show that oil palm empty fruit bunches compost can be used as a source of humic acid
Antioxidant Activity Test of Red Spinach’s Extract (Blitum rubrum) in Ethanol Solvent and Water Solvent with DPPH
Get PDFThe study of red spinach antioxidants (Blitum rubrum) in two types of solvents i.e ethanol and water has been performed. The purpose of this study was to determine the antioxidant activity of red spinach extract from Tinombo Selatan district, Central Sulawesi. Red spinach was macerated in ethanol and water to obtain variations of extract concentrations of 20, 40, 60, and 80 mg/L. Free radicals used were DPPH reagents while vitamin C was used as a positive control. The measurement of absorbance of red spinach’s extract was conducted by spectrophotometric. The results showed that IC50 extract of red spinach in ethanol and water were 51.404 mg/L and 52.227 mg/L, while the value of IC50 vitamin C in ethanol and water solvent was 43.241 mg/L and 140.507 mg/L. Based on the IC50 red spinach’s extract in ethanol and water have strong antioxidant activity
The Effect of Application Cooperative Learning Model of Think-Pair-share (TPS) and Means –End Analysis (MEA) Types on Students Learning Outcomes of Tenth Grade on Redox Material at SMA Negeri 7 Palu
Get PDFThis study aimed to analyze the effect of the application of the Think-pairs-Share and Means- Ends Analysis learning Achievement of a student on reduction-oxidation in class X at SMAN 7 Palu. This study was a ween experiment with a static group pretest-posttest design. This study was carried out by holding two groups of class X Science 1 as the experimental one group (n = 25) and class X science 2 as the experimental two groups (n = 28). Results of the data analysis showed the average value (X2) of the experimental one class was 68.56 with a standard deviation of 16.97 dan (X2) of the experimental two class was 56.14 with a standard deviation of 13.12. Based on the hypothesis test results with t-test statistical of two parties obtained –ttable ≤ tcount ≥ + ttable (tcount = 1.89 and ttable = 1.67) with a significance level of α= 0.05 and degrees of freedom of 51, then Ho was rejected and Ha was accepted. It can be concluded that there was an effect of the application of the think-pairs–share and means-ends analysis learning model toward learning achievement of students in class X at SMAN 7 Palu on reduction-oxidation
Analysis of Cyanide Acid Content in Cassava (Manihot esculenta) Based on Storage Time
Get PDFCassava is a tuber of cassava plants which is a source of carbohydrates that can be consumed as food and as snack foods such as chips. However, cassava and the leaves contain cyanide acid (HCN) which is dangerous for the human when consumed in excess. Cyanide acid reduction can be done by washing as well as immersion because of its volatile nature. The aim of this research is to investigate the difference of cyanide acid (HCN) content on peeled and unpeeled cassava with the variation of storage time 0, 2, 4, 6, and 8 days. A preliminary test was done to know the existence of cyanide acid (HCN) in cassava. Method analysis of cassava was titrated with the NH4CNS solution using the argentometric principle of the Volhard method. The results showed that cyanide acid (HCN) content in peeled cassava was higher than unpeeled cassava which was 3.9, 4.7, 5.2, 5.6, and 6.0% respectively for shelled cassava and 3.9, 4.6, 5.1, 5.5, and 5.9% respectively for unpeeled cassava
Crude Bromelain Enzyme Activities Based on Maturity Level of Pineapple
Get PDFUtilization 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