The main purposes for this work are to formulate and characterize the infrared (IR) and magnetic moment of the compounds resulted from the slow titration of copper(II) nitrate with sodium hydroxide and in the reverse procedures in an aqueous solution. The titration is carried out with various concentrations and at a constant temperature, ⁓ 19 oC, and monitored using pH meter with the rate of the titration⁓ 1 mL per minute. The corresponding data of change in mole ratio of Cu2+/OH- against pH reveals that the end point of the titration occurs at pH about 8, leading to stoichiometry formula, 3Cu(NO3)2.5Cu(OH)2, but Cu(NO3)2.5Cu(OH)2 in the reverse procedure (OH-/Cu2+). The pale blue for the former but deep blue compounds were isolated and then characterized IR spectroscopy and magnetic moment. Both compounds containing nitrate ion are evident from the corresponding IR spectra, and their magnetic moment values which were found in the range of 1.7-1.9 BM, are to be normal for copper(II) salt corresponding to one unpaired electron in the electronic configuration.
AbstrakPenelitian ini bertujuan untuk memvalidasi metode analisis siklamat secara spektrofotometri dan turbidimetri dalam sampel minuman jelly drink rasa mangga secara spektrofotometri dengan pereaksi hipoklorit, spektrofotometri ultra violet (tanpa pereaksi) dan turbidimetri. Kurva kalibrasi larutan standar natrium siklamat pada metode spektrofotometri dengan pereaksi hipoklorit, spektrofotometri UV (tanpa pereaksi), dan turbidimetri berbentuk linier. Daerah kerja masing-masing metode secara berturut-turut pada konsentrasi (211,08); (16,434); dan (1,852-6,172) ppm. Batas deteksi masing-masing metode secara berturut-turut sebesar 53,6028; 0,5833; dan 0,2723 ppm. Batas kuantitasi masing-masing metode secara berturut-turut sebesar 66,9948; 1,9443; dan 0,8068 ppm. Metode analisis siklamat secara spektrofotometri dengan pereaksi hipoklorit mempunyai presisi dan akurasi yang baik, sementara metode analisis siklamat secara spektrofotometri UV mempunyai presisi baik dan akurasi kurang baik. Sedangkan metode analisis siklamat secara turbidimetri mempunyai presisi dan akurasi kurang baik. (211.36-747.08); (16.000-146.434); and (1.8521-6.1717) ppm. The detection limit of each method successively were 53.6028; 0.5833; and 0.2723
This study was aimed to develop a method for metal analysis in continuous integration using voltammetry techniques. The research subject was copper(II) ions. The objects of research were linearity, scan rate, repeatability of readings, and the presence of Cu(II) levels in well water samples. In this study, a selective electrode was developed with a solid membrane voltammetry system using differential pulse voltammetry measurement. The results showed the regression line of voltammetry method, y = 10.265 ln (x) + 330.47, with a correlation value of 0.9654, the optimum scan rate was 10 mV/s, and within five repetitions of each measurement for one electrode, it showed good repeatability. Meanwhile, the result of regression with the UV-Vis spectrophotometric method for Cu(II) was y = 0.12386x + 0.00879 with a correlation value of 0.9943. The voltammetry method was found to be much better than the UV-Vis method because it was able to be used for analysis up to a concentration of 6.35 × 10–4 ppm (or 1.00 × 10–11 M), while the UV-Vis method was only able to analyze up to 1.5 ppm (or 2.36 × 10–5 M).
Penelitian ini bertujuan untuk memisahkan ion logam besi dan mangan pada air sumur (dalam) menggunakan metode adsorpsi kolom. Berdasarkan penelitian, diketahui efektivitas metode adsorpsi kolom untuk penurunan kadar logam besi dan mangan pada air sumur, efisiensi waktu penjerapan terhadap ion logam besi dan mangan, serta kondisi air sumur sebelum dan sesudah adsorpsi. Penelitian dilakukan pada air sumur (dalam) Wonoboyo, Kecamatan Jogonalan, Kabupaten Klaten. Proses adsorpsi menggunakan kolom berisi zeolit dan karbon aktif sebagai adsorben. Pada penelitian ini efektivitas pemisahan logam besi dan mangan dari air sumur (dalam) diketahui dari nilai efisiensi penjerapannya. Analisis logam besi dan mangan dilakukan dengan Spektrofotometri Serapan Atom (AAS). Selain itu juga dilakukan uji parameter air yaitu pH dan TDS. Hasil penelitian menunjukkan bahwa semakin lama proses adsorpsi, maka efektivitas adsorben zeolit dan arang aktif dalam menurunkan kadar Fe dan Mn meningkat. Efisiensi penjerapan cukup tinggi dengan rata-rata 97,50% untuk Fe dan 98,33% untuk Mn. Air yang sebelumnya keruh menjadi jernih dengan pH dan TDS yang semakin kecil, sehingga air lebih aman dikonsumsi karena semakin jauh dari nilai ambang batas yang ditetapkan dalam SNI dan permenkes RI N0.492/MENKES/PER/IV/2010.
This Research aim to know: 1) the potential difference which can degrade the heavy metal ion concentration of Cu(II), Cr(III), Pb(II), and Zn(II) in liquid waste of electroplating maximally, 2) the efficiency of degradation of heavy metal ions concentration of Cu(II), Cr(III), Pb(II), and Zn(II) in liquid waste of electroplating at optimal potential difference, and 3)the potential difference yielding the nicest coat quality pursuant to its physical appearance.This research early with the preparation electroplating: 1) the preparation of sample liquid waste, 2) platinum electrode,and 3) iron metal to be arranged in layers. The instrument of this research is potentiometers Shimadzu NES_5F. Process the electroplating has been done at variations of potential difference that are 2.0; 2.5; 3.0; 3.5; 4.;, 4.5; and 5.0 V. Analysis of concentration of metal ions in liquid waste of electroplating before and hereafter process the electroplating have been done by atomic absorbtion spectrophotometric (AAS). Perception result of coating have been done visually by researcher. The result of this research are 1) the potential differences which can degrade the heavy metal ions concentration of Cu(II), Cr(III), Pb(II), and Zn(II) in liquid waste of electroplating maximally is 4 V, 2) efficiency of degradation of heavy metal ions concentration of Cu(II), Cr(II), Pb(II), and Zn(II) in liquid waste of electroplating at optimal potential difference successively are 21.30; 72.37; 51.00; and 58.60 %, and 3) potential difference yielding the nicest coat quality pursuant to its physical appearance is 4 V.
The aims of this research to determine of the optimum of formaldehyde concentration, teh optimum of electrodeposition time and the optimum pH of solution. In addition, this research also aims to determine the character Cu deposite at optimum operational. The sample in this research was used real electroplating liquid waste from Kotagede Yogyakarta.done at various formaldehyde concentration Electrodeposition was done at various formaldehyde concentration, electrodeposition time and varoius of pH. The optimum conditions could be seen the maximum efficiency. It could be obtained by measuring the final concentration of Cu2+ after electrodeposition process by Atomic absorption spectrophotometry. The character of deposit could be seen by visual and X-ray Diffraction. The result of this research showed that the optimum of formaldehyde concentration as reducing agent was 0.3 M. the optimum time was 4 hours and the optimum of pH 9. The character of deposte was contained Cu deposite and more subtle than deposite which electrodeposited without formaldehyde. Keywords: electrodeposition, formaldehyde, reducing agent
The aim of the study was to identify 1) the level of emotionalquotient of the lecturers of Mathematics and Natural Sciences basedon their gender at various universities in the Province ofYogyakarta, and 2) the differences in the emotional quotient amongthe lecturers. The study was ex-post facto research. As the researchvariable, emotional quotient was defined as the scores resultingfrom the EQ questionnaire to include self emotion knowing, selfemotion management, self motivation, others emotion knowing, andrelationship construction. The population of the study wasdesignated to be the lecturers of Mathematics and Natural Sciencesat various universities in Yogyakarta Province. The sample of thestudy consisted of 141 lecturers, 72 male and 69 female, taken bypurposive random sampling technique. The instrument was thequestionnaire adapted from relevant references (Ridwan Saptoto:2002). Data were analyzed qualitatively by conversion criteria. EQdifferences were computed statistically by a t-test. Results showedthat the average score of EQ levels of male and female lecturerswere 79.6% (very high criteria) and 78.2% (high criteria). Thedifference (1.4%) was not statistically significant
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