Cork stoppers. Determination of oxidizing residues. Iodometric titration method

2007 ◽  
1945 ◽  
Vol 18 (3) ◽  
pp. 663-666 ◽  
Author(s):  
C. L. Luke

Abstract The range of the hydriodic acid reduction-iodometric titration method for the determination of sulfur in semimicrosamples of rubber has been extended to provide for the analysis of macrosamples containing as much as 100 mg. of sulfur.


2014 ◽  
Vol 2014 ◽  
pp. 1-10
Author(s):  
A. V. Churikov ◽  
S. L. Shmakov ◽  
V. O. Romanova ◽  
K. V. Zapsis ◽  
A. V. Ushakov ◽  
...  

A methodology for quantitative chemical analysis of the complex “borohydride-borate-hydroxide-carbonate-water” mixtures used as fuel in the borohydride fuel cell was developed and optimized. The methodology includes the combined usage of the acid-base and iodometric titration methods. The acid-base titration method, which simultaneously uses the technique of differentiation and computer simulation of titration curves, allows one to determine the contents of hydroxide (alkali), carbonate, and total “borate + borohydride” content. The iodometric titration method allows one to selectively determine borohydride, so the content of each of OH-, BH4-, BO2-, and CO32- anions in the fuel becomes estimated. The average determination error depends on the number and ratio of compounds in a mixture. Specific details of the analysis of various fuel mixtures are discussed.


2017 ◽  
Vol 1 (1) ◽  
pp. 89
Author(s):  
Indah Purwaningsih ◽  
Supriyanto Supriyanto

Abstract: Chlorine is a green halogen-shaped halogen gas at normal temperature and serves as bleach, stain remover and disinfectant. Chlorine is now widely used for bleaching rice so that less quality rice looks like quality rice. Chlorine is very toxic and causes mucous membrane irritation, highly reactive and very powerful oxidizer. The purpose of this research was to determine the difference of chlorine level in chlorinated rice washed once, twice and 3 times. The sample in this study amounted to 11 samples calculated by replication formula. Each sample was treated 3 times, ie 1 washed once, 2 washed twice and washed 3 times. The samples then examined by iodometric titration method. Based on the results of the study using ANOVA test, 11 samples obtained the average value of chlorine after washed once amount of 0.0176%, after washed twice amount of 0.0111%, and after washed 3 times amount of 0.0052% with the value significance p = 0.03 (p <0.05) at 95% confidence level which means there was a significant difference between chlorine levels in chlorinated rice washed once, twice and 3 times.Abstrak: Klorin merupakan unsur halogen berbentuk gas berwarna kuning kehijauan pada suhu normal danberfungsi sebagai pemutih, penghilang noda maupun desinfektan. Klorin sekarang banyak digunakan untuk bahan pemutih beras agar beras yang kurang berkualitas tampak seperti beras berkualitas. Klorin sangat toksik dan menyebabkan iritasi membran mukosa, sangat reaktif dan merupakan oksidator yang sangat kuat. Tujuan dari penelitian ini ialah untuk mengetahui perbedaan kadar klorin pada beras berklorin yang dicuci sebanyak 1 kali, 2 kali dan 3 kali. Sampel dalam penelitian ini berjumlah 11 sampel yang dihitung dengan rumus replikasi. Setiap sampel diberi perlakuan sebanyak 3 kali, yaitu 1 kali pencucian, 2 kali pencucian dan 3 kali pencucian. Sampel penelitian kemudian diperiksa dengan metode titrasi iodometri. Berdasarkan hasil penelitian menggunakan uji Anova secara komputerisasi terhadap 11 sampel diperoleh nilai rata-rata kadar klorin setelah 1 kali pencucian sebesar 0,0176 %, setelah 2 kali pencucian sebesar 0,0111 %, dan setelah 3 kali pencucian sebesar 0,0052 % dengan nilai signifkansi p = 0,03 (p<0,05) pada tingkat kepercayaan 95% yang artinya ada perbedaan yang bermakna antara kadar klorin pada beras berklorin yang dicuci sebanyak 1 kali, 2 kali dan 3 kali.


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