Jurnal Akademika Kimia
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Improvement Physics 1 of Chemistry Learning Outcomes Through Project-Based Learning Models (PjBL) Using Quizizz Online Learning Media
Get PDFImproving cognitive abilities, namely learning outcomes is one of the objectives of learning. Learning outcomes can be improved through the use of creative, innovative learning models in accordance with the current curriculum, the 2013 revised curriculum. This study aims to determine whether there is an increase in Physics Chemistry Learning Outcomes 1 through the Project-based Learning (PjBL) Learning Model using Quizizz online learning media. Based on the results of the normality and homogeneity test, the data is normally distributed with the value of the normality test result of 0.638 (sig 0.05) and homogeneous with the homogeneity test result value of 0.144 (sig 0.05). The results of statistical analysis of research data using the paired t-test hypothesis test results obtained tcount = 17,685 (sig 0.00) and ttable = 0.684 (sig 0.05), it is concluded that there is an increase in learning outcomes in Physics Chemistry 1 through the Project-based Learning (PjBL) learning model using Quizizz online learning media because tcount˃ ttable. A further test is the gain test, to determine the level of improvement in learning outcomes. The results of the analysis using the gain test, the gain value of 42.51%, with the medium category
Citric Acid Extraction in Citrus hystrix Peels as an Alternative Material for Reducing Water Hardness
Get PDFWater hardness will have a destructive impact if consumed in a long time. Hard water contains high calcium contents, including inorganic calcium. The accumulation of calcium in the body at a specific time causing kidney stones, and some will settle in the blood that causing calcification which can be fatal to health. An alternative is needed to reduce the level of water hardness. This study aimed to determine the effect of using citric acid on citrus hystrix peels on water hardness. Citric acid was obtained through the maceration extraction method from citrus hystrix. The citric acid extract was made into several concentrations of 50, 100, and 150 ppm then added to hard water. Determination of decreased total water hardness after adding citric acid used method complexometry titration. The results of the analysis show that citric acid is able to reduce water hardness of the sample water from Palu city area
Effect of Different Types of Extractants in the Separation of Rare Earth Metals using Emulsion Liquid Membrane Method: A Review
Get PDFRare Earth Metals (REMs) are minerals which needed in modern technology because it has unique chemical, catalytic, electrical and paramagnetic properties, so REMs have the potential to be applied in various fields. The similarity in the physical and chemical properties of REMs causes them to be difficult to separate from their parent minerals. Emulsion Liquid Membrane is an effective and efficient method for REMs purification and separation because in practice it only requires a small amount of solvent, the diffusion rate and mass transfer are high, fast, and simultaneous compared to the solvent extraction method which requires many extraction steps and requires a lot of solvents. In the emulsion liquid membrane method, one of the factors that can determine the success of the extraction process is the selectivity of the ligands/extractants. The extractants must be highly selective against the target REM ions, both in the external aqueous phase and the internal aqueous phase. Therefore, this review aimed to determine the selectivity of various types of extractants such as D2EHPA, Cyanex 302, Cyanex 572, (RO)2P(O)OPh-COOH, Aniline, and TBP on extraction efficiency and stripping efficiency in the separation of rare earth metals through the emulsion liquid membrane method
Identification Chemical Compositions of Lemongrass Plant (Cymbopogon nardus L.) Dawan Tribe, Oenenu Village, North Central Timor Regency
Get PDFLemongrass (Cymbopogon nardus L.) is a local natural resource used by the Dawan tribe as an alternative for mosquito repellent. The utilization of these plants cannot be separated from the content of compounds found in these plants. Therefore, it is necessary to analyze the content of bioactive compounds from lemongrass (Cymbopogon nardus L.). This research method includes sample preparation, isolation and identification of compounds, and antioxidant activity analysis. The results of this study that there were three main components of citronella oil, namely geraniol, citronellol, and citronellal, with a higher percentage of geraniol, namely 18.82%. The compounds contained in lemongrass oil have a weak antioxidant activity with IC50 681.48 mg/mL
Application of Inquiry Learning Model with Lesson Study (LS) Pattern on Student Learning Outcomes in Colloid System Material
Get PDFThis study aimed to know the effect of applying the inquiry learning model with lesson study (LS) pattern on student learning outcomes in colloid system material in class XI SMA Negeri 1 Sigi. This type of research was a quasi-experiment with an equivalent post-test design. Samples were determined by the purposive sampling method. The sample used in this study was students of class XI MIA 3 as an experimental class with 24 students and XI MIA 4 students as a control class with 20 students. The processing of student learning outcomes data used a non-parametric analysis of the Mann-Whitney U-Test test. The results showed that the mean value of the experimental class was higher than the control class, which was 23.98>15.82. Results of statistical analysis sig. 2-tailed was (0.019) <0.05 and Zcalculation (-2.336) < Ztable (-1.96), based on decision-making criteria, it stated if the value of -Zcalculation<Ztable then H0 is rejected. Therefore, it can be concluded that there is the effect of applying the inquiry learning model with lesson study (LS) pattern on student learning outcomes in colloid system material in class XI SMA Negeri 1 Sigi
Application of Clove Leaf Oil (Syzygium aromaticum L.) on Preservation of Milkfish (Chanos chanos)
Get PDFClove leaf oil (Syzygium aromaticum L.) is obtained from distilling clove leaves. This study aimed to examine the effect of clove leaf oil on the preservation of milkfish meat. Clove leaf oil was obtained by steam distillation and purified by a simple distillation method. The number of microbes was determined using the total plate count (TPC) method, while the organoleptic test used a level of preference for color, smell, texture, and taste. The results showed that the pH and the number of fish meat bacteria at a concentration of 8%, when left for one day, were 6.61 and 2.46 × 10-7 CFU/mL, while the three days was 7.2 and 2.98 × 10-7 CFU/mL, a concentration of 10% in 1 day which was 6.64 and 2.03×10-7 CFU/mL while the three days was 7.25 and 2.54 × 10-7 CFU/mL and a concentration of 12 % in 1 day was 6.67 and 1.83 × 10-7 CFU/mL while three days was 7.57 and 2.07 × 10-7 CFU/mL, besides that from organoleptic test data the panelist preference rate was more significant in the concentration of 12 % then the concentration of 10 and 8 %, respectively. The results showed that at a concentration of 12%, it was a good concentration to be used as preservation compared to a concentration of 10 % and a concentration of 8%, both for a 1-day and a 3-days. This shows that the higher the concentration of clove leaf oil, the greater the ability to preserve fish meat
A Prenylated Flavonoid from the Methanol Fraction of Breadfruit Root (Artocarpus communis)
Get PDFBreadfruit (Artocarpus communis) is a tropical fruit plant that belongs to the genus Artocarpus of the Moraceae family. Prenylated flavonoid compounds were isolated from the methanol fraction of breadfruit root wood using maceration, partitioning, and chromatography methods, while characterization was carried out through phytochemical tests and 1H-NMR spectrum data analysis. The K1D2 (P1) compound obtained was a yellow solid with a mass of 5 mg. The phytochemical test of the K1D2 (P1) compound gave positive results for the flavonoid group. The 1H-NMR spectrum data (CDCl3, 500 MHz) of compound K1D2 (P1) showed a typical chemical shift at δH 13.42 (1H, s, 5-OH) for the hydroxy groups associated with carbonyl; 7.68 (1H, d, J = 8.5 Hz, H-6 ′); 6.71 (1H, dd, J = 16.0; 7.1 Hz, H-10); 6.56 (1H, d, J = 16.0 Hz, H-9); 6.54 (1H, dd, J = 8.5; 1.8 Hz, H-5 ′); 6.46 (1H, s, H-3); 6.42 (1H, d, J = 1.8 Hz, H-3 ′); 6.26 (1H, d, J = 9.3 Hz, H-14); 5.42 (1H, d, J = 9.3 Hz, H-15); 3.94 (3H, s, 2′-OCH3); 2.47 (1H, m, H-11); 1.97 (3H, s, H-17); 1.69 (3H, s, H-18), and 1.10 (6H, d, J = 6.7 Hz, H-12 and H-13). Based on the results of phytochemical tests and analysis of 1H-NMR spectrum data compared with literature data, it showed that the isolated K1D2 (P1) compound is 4 ′, 5-dihydroxy-6,7- (2,2-dimethylpirano) -2'-methoxy- 8γ, γ-dimethylallylflavone (1)
Analysis of Calcium (Ca) and Potassium (K) Levels in Mackerel (Rastrelliger sp.) Bones
Get PDFMackerel (Rastrelliger sp.) is one of the potential pelagic fish in Indonesia and in almost all Indonesian waters. In general, fish bones contain many essential ingredients for the body and can be processed into fish bone flour. This study aimed to determine calcium (Ca) and potassium (K) levels in mackerel (Rastrelliger sp.) bones. Calcium and potassium levels were determined using an atomic absorption spectrophotometry (AAS). Results of the analysis showed that the water, ash, and biomass levels of the sample were 10.53, 18.26, and 71.21%, respectively. Analysis of calcium and potassium levels at wavelengths 422.7 nm and 766.5 nm obtained an average of 508.15 and 36.37 mg/100g. The results indicate that the calcium level is higher than the potassium level in mackerel (Rastrelliger sp.) bones
Phytochemical Screening and Antioxidant Activity Test of Red Onion (Allium ascolinicum L.) Extract Variety of Palu Valley
Get PDFThe red onion of Palu valley variety is a plant that is widely found in Palu area and regarded as a leading commodity in Central Sulawesi. The purpose of this study was to examine the secondary metabolite compounds contained in red onion (Allium ascolinicum L.) of Palu valley variety and its antioxidant activity. Antioxidant activity test in this study used DPPH (1,1-Diphenyl-2-Pikrilhidrazil) as a source of free radical, and vitamin C as the comparison. The antioxidant activity of red onion extract was analyzed using a UV-Vis spectrophotometer. The red onion tuber powder was extracted by maceration using ethanol solvent. Qualitative test of onion powder showed positive results on alkaloids, flavonoids, and tannin compounds. The samples and vitamin C were tested for antioxidant activity in various extract concentrations of 10, 30, 50, 70, and 90 ppm. The results showed that red onion extract of Palu valley variety presented an IC50 value of 38.548 ppm, and vitamin C presented an IC50 value of 22.646 ppm. Based on these values, the red onion (Allium ascolinicum L.) extract is categorized as a very strong class of antioxidant which can be used as a source of natural antioxidant
Determination of Iron (Fe) and Copper (Cu) on Pellets from Fermentation of Mozambique Tilapia (Oreochromis mossambicus) using Goat Dirt Adhesives
No full textTilapia fish waste and livestock manure are an environmental problem, besides being smelly pollution will also cause disease disorders for humans. The purpose of this study was to determine the levels of micronutrients of iron (Fe) and copper (Cu) on pellets from the fermentation of waste tilapia (oreochromis mossambicus) using adhesive goat manure. Fish waste was fermented for 15 days and mixed with adhesive goat manure and then was processed in a pellet making machine. The Fe and Cu levels were determined using Atomic Absorption Spectrophotometer (AAS). The results of the determination of levels Fe was 137 ppm and for Cu was 4.1 ppm