Bahrizal Bahrizal
Jurusan Kimia FMIPA Universitas Negeri Padang

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PENGARUH PENGGUNAAN SUMBER SILIKA ALUMINA TERHADAP KARAKTERISTIK SEMEN YANG DIHASILKAN Mawardi, Mawardi; Sihaloho, Rianti; Bahrizal, Bahrizal
Periodic Vol 1, No 2 (2012)
Publisher : Jurusan Kimia FMIPA UNP

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24036/p.v1i2.2519

Abstract

A study concerning about the effect using of source silica alumina that shape napa land from Solok Selatan to characterization of cement produce. In this study can learning the effect using napa land to particle size of cement with tested the waste on sifter, not soluble, lose glowing, press force and composition chemichal of cement with XRF based variety composition is 0%, 5% dan 9.5% from total number of cement. Then the results are particle size, not soluble part and lose glowing of cement that produces increase as a increase using of napa land. However, not be valid on press force in 3, 7 and 28 days tested produce decrease. It caused the particle size of cement is increase as a increase of napa land composition. The largest using is 9.5% of total number of cement can be fill SNI standard 15-7064-2004.
ANALISIS KADAR ASAM ASKORBAT DAN ASAM BENZOAT DALAM MINUMAN RINGAN DENGAN HPLC MENGGUNAKAN FASA GERAK METANOL DAN BUFFER ASETAT Sanjaya, Rani; Oktavia, Budhi; Bahrizal, Bahrizal
Periodic Vol 1, No 2 (2012)
Publisher : Jurusan Kimia FMIPA UNP

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24036/p.v1i2.2523

Abstract

Penelitian ini bertujuan untuk menentukan kondisi optimum untuk pemisahan dan penentuan kadar asam askorbat dan asam benzoat yang berperan sebagai pengawet dalam minuman ringan yang beredar di pasaran dan di lingkungan sekolah dengan menggunakan HPLC. Hasil penelitian menunjukkan bahwa kondisi optimum HPLC yang menggunakan fasa gerak metanol dan buffer asetat berada pada laju alir 1 ml/mnt, Kolom ODS C18, ?= 240 nm, pH buffer 3.5, dilakukan secara elusi gradien yang dimulai pada komposisi fasa gerak 5:95 hingga 50:50 selama 5 menit. Dari hasil uji kadar sampel minuman ringan yang dijual di lingkungan sekolah tidak ditemukan asam askorbat dan asam benzoat sebagai bahan pengawet, sedangkan untuk minuman ringan yang beredar di pasaran dari 5 sampel yang diuji ditemukan sampel yang mengandung asam benzoat yang melebihi batas maksimum yang diizinkan yang terdapat pada sampel C yaitu 676 ppm, sedangkan kadar yang diizinkan menurut SNI 01-0222-1995 untuk asam benzoat adalah 600 ppm, sedangkan untuk kandungan asam askorbat terbanyak terdapat pada sampel A yaitu 2869 ppm.
ANALISIS SILIKON (SI) DAN MAGNESIUM (MG) DALAM TANAH LEMPUNG DI KABUPATEN TANAH DATAR SECARA SPEKTROFOTOMETRI SERAPAN ATOM Angraini, Wiwit; Amrin, Amrin; Bahrizal, Bahrizal
Periodic Vol 1, No 2 (2012)
Publisher : Jurusan Kimia FMIPA UNP

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24036/p.v1i2.2527

Abstract

Telah dilakukan penelitian tentang analisis silikon dan magnesium dalam tanah lempung yang terdapat di Kabupaten Tanah Datar secara Spektrofotometri Serapan Atom. Penelitian ini bertujuan untuk menentukan kandungan silikon (Si) dan magnesium (Mg) dengan jenis pelarut, ukuran partikel dan konsentrasi pelarut terbaik secara spektrofotometri serapan atom. Analisis silikon dan magnesium dilakukan dengan menggunakan metoda destruksi basah, dimana proses pendestruksian dilakukan dengan beberapa variasi yaitu variasi pelarut : HF, HCl pekat, HNO3 pekat, dan HCl-HNO3 pekat (3:1), variasi ukuran partikel yaitu ? 63 ?m, > 63 - ? 75 ?m, dan > 75 - ? 90 ?m serta variasi konsentrasi pelarut HF yaitu 23 M, 18 M, 12 M, 6 M dan variasi konsentrasi pelarut HCl yaitu 12 M, 9 M, 6 M dan 3 M. Hasil penelitian menunjukkan bahwa kandungan silikon terbaik didapatkan menggunakan pelarut HF 12 M dengan ukuran partikel ?63µm yaitu 26,79% dan kandungan magnesium terbaik didapatkan menggunakan pelarut HCl 9 M dengan ukuran partikel ?63 µm yaitu 1,08%.
KONVERSI BIOETANOL HASIL FERMENTASI DARI UBI JALAR PUTIH (IPOMOEA BATATAS LAM.) MENJADI ASAM ASETAT MENGGUNAKAN ACETOBAKTER ACETI Kasari, Novi; Iryani, Iryani; Bahrizal, Bahrizal
Periodic Vol 1, No 2 (2012)
Publisher : Jurusan Kimia FMIPA UNP

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24036/p.v1i2.2522

Abstract

Manufacture of acetic acid fermentation occurs in two stages, namely alcoholic fermentation and acetic acid fermentation. In alcoholic fermentation, materials containing starch or glucose converted into bioethanol by Saccharomyces cereviciae. After that in the second stage of bioethanol produced is oxidized to acetic acid by Acetobakter aceti. Has done research on the conversion of bio-ethanol from the fermentation of white sweet potato (Ipomoea batatas LAM.) to acetic acid using Acetobacter aceti. This study aimed to determine the amount of inoculum Acetobacter aceti and fermentation to produce acetic acid with the highest concentration. The research was conducted using completely randomized design (CRD) with two factors: the first factor is the amount of inoculum consists of three variations, namely 5, 10 and 15% (v/v), and the second factor is the length of fermentation which consists of 4 variations ie 3, 6, 9, 12 days. In this study, the concentration of ethanol obtained at 7.05422% with simultaneous fermentation by Aspergillus niger and Saccharomyces cereviciae with 2:1 ratio and fermentation time 56 hours. While the highest concentration of acetic acid is obtained in the addition of 10% inoculum and fermentation time of 12 days is equal to 0.553%.
Penggunaan Teknik Talking Chips pada Model Kooperatif Hasil Belajar dalam Pembelajaran Tata Nama Senyawa dan Persamaan Reaksi Kimia di SMAN 2 Pariaman Bayharti, Bayharti; Bahrizal, Bahrizal; Fitriani, Rahmi
Jambura Journal of Educational Chemistry Vol 12, No 1 (2017): Februari
Publisher : Jambura Journal of Educational Chemistry

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (29.724 KB)

Abstract

The goal of this study is to know the effect of using techniques talking chips on the cooperative learning in study of nomenclature of compounds and the chemical reaction at SMAN 2 Pariaman. The model used is a cooperative learning with talking chips technique that can improve students' learning activity. This research is a quasi-experimental research which design of Randomized Control Group Posttest Only Design. The population of this study were all students of class X SMAN 2 Pariaman. The sampling technique used was cluster sampling X.1 class is experimental and X.2 class is the control class. The data collection was done by administering tests at the end of the study. This research found that the average value of student score at experimental class is 76.33 and those of control class is 69.4. Both of these data are found normal and homogen. Data analysis used was t-test on a real level of 0.05 that obtained tcount = 2.605 and ttabel1.67. This means tcount> ttabel, and the research hypothesis is accepted. It can be concluded that there is a significant increase from the results of studying chemistry by using the technique of talking chips on the cooperative model in study of nomenclature of compounds and chemical equations.
PERBANDINGAN HASIL BELAJAR MENGGUNAKAN MODEL PEMBELAJARAN KOOPERATIF TIPE STAD DAN CRH PADA MATERI HIDROLISIS GARAM Amida, Nadia; Andromeda, Andromeda; Bahrizal, Bahrizal
Alotrop Vol 2, No 2 (2018)
Publisher : FKIP University of Bengkulu

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Abstract

Lesson about  hydrolysis  requires students to understand the concepts hydrolyzed from  type of salt which is then applied in the calculation. In  learning process, students direct involvement is necessary, so that it is used a method that can increase the activity of students. Student Teams Achievement Division (STAD) cooperative learning and Course Review Horey (CRH) expected to create learning that has caharacterized as student centered.  This research aims to reveal students' learning outcomes using STAD cooperative learning and CRH on the hydrolisis material in class XI SMAN 8 Padang. This type of research is experimental research using a randomized study design Control Group Posttest-Only Design is expanded. The study population was a class XI IPA SMAN 8 Padang. Giving  a test at the end of the study as many as 25 pieces of matter objectively. Results of tests of normality and homogeneity of the two classes that both classes of samples obtained samples were normally distributed and had homogeneous variance. After being tested on a real level t = 0.05 with degrees of freedom (df) of 59 obtained t of 2.53 while t table of 1.67. From the research shows that the learning outcomes of students with STAD cooperative learning model is significantly higher than the results of student learning with cooperative learning model CRH hydrolysis of salts in the material in class XI of SMAN 8 Padang.
PREPARASI DYE SENSITIZED SOLAR CEL MENGGUNAKAN EKSTRAK ANTOSIANIN KULIT BUAH MANGGIS (Garcinia Mangostana L) Maulina, Anna; Hardeli, Hardeli; Bahrizal, Bahrizal
Sainstek : Jurnal Sains dan Teknologi Vol 6, No 2 (2014)
Publisher : IAIN Batusangkar

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (599.364 KB) | DOI: 10.31958/js.v6i2.115

Abstract

This study aims to determine the effect of the concentration of semi-solid electrolyte/polymer gel and determine the effect of the dye absorption technique on TiO2 paste the resulting DSSC efficiency. The results obtained by XRD characterization of TiO2 crystal phase is anatase and rutile TiO2 with a crystal size of 30.27 nm. Based of testing the light absorption of dye extract of purple sweet potato is known that the spectrum of the dye can absorb light at 533 nm wavelength maximum. The result of the conversion of sunlight into electrical energy obtained the highest value is at the highest PEG concentration at 0.1 M is 0,38% for TiO2 paste is mixed directly with the dye and 0,23% for TiO2 paste soaking in the dye for 24 hours using an electrolyte semi-solid/gel polymer with an area of 1 cm2.Key words: Anthocyanin, DSSC, semi-solid electrolyte, FTIR, UV-Vis, XRD