溴化钾-溴酸钾标准溶液的标定

溴化钾-溴酸钾标准溶液的标定 应用资料碘量瓶中加入50mL冰乙酸和1mL浓盐酸，并将其放入冰水浴中冷却10min左右。然后，不断地摇动瓶子，同时用校准过的10mL滴定管以每秒1滴或2滴的速度向其中加入5mL±0.01mL溴化钾-溴酸钾标准溶液。立刻盖上瓶塞，摇匀，再次放到冰水浴中。然后在瓶口处加5mL碘化钾溶液。5min后从冰水浴中取出碘量瓶，慢慢地打开瓶塞，让碘化钾溶液流入瓶中，剧烈地摇动。用100mL水冲洗瓶塞、瓶口及瓶壁，然后迅速地用0.1mol/L硫代硫酸钠溶液进行滴定。KMAPAT-0250en京都電子工業株式会社KYOTO ELECTRONICSMANUFACTURING CO.，LTD. APAT-0250en Application NoteStandardization of bromide-bromate standardsolution 1. Scope Caution This measurement is performed using organic solvents and strong acids. When youfollow this application note， wear masks， gloves， protective equipment， etc. Theautomatic potentiometric titrator should be installed and used in fume hoods wherelocal exhaust ventilation is possible. Bromide-bromate standard solution is used as a titrant to determine the bromine value andbromine index in various standards such as ASTM. This Application Note introduces thestandardization of 0.25 mol/L bromide-bromate standard solution according to ASTM D1159.The reaction formula for the standardization is as follows (1) bromine formation， (2) displacementreaction with potassium iodide， (3) titration by sodium thiosulfate solution. The concentration ofthe adjusted bromide-bromate solution is determined by titrating with a sodium thiosulfatesolution of known concentration. 2. Precautions Before starting measurements each day， purge the titrant several times between the reagent bottleand the burette to equalize the titrant concentration， then discharge about 10 mL of the titrantbetween the burette and the titration nozzle. 3. Post-measurement procedure Clean the electrodes and titration nozzle with pure water in that order， then immerse them in purewater. If the titration nozzle is left exposed to the air， the components in the titration solution willprecipitate out， and the nozzle will clog. 4. Apparatus Main unit Automatic potentiometric titrator (Preamplifier STD) Electrode Combined platinum electrode (C-272) Temperature compensation electrode (T-171) 京都电子工业株式会社-可睦电子(上海)商贸有限公司 上海市徐汇区宜山路333号1201室 电话：021-54488867 电邮： kemu-kem@163.com网址： http：//www.kem-china.com 5.Reagents Titrant 0.1 mol/L Sodium thiosulfate solution Reagents Hydroxy chloride (35 wt%)， Glacial acetic acid Additive reagents150 g/L Potassium iodide solution 6. Procedure 1) 50 mL of glacial acetic acid and 1 mL of hydrochloric acid (35 wt%) are added to a 100mLErlenmeyer flask with a stopper and cooled at 0 to 5 ℃ for 10 minutes. 2) Drop 5 mL of 0.25mol/L bromide-bromate solution into a cooled reagent， close the stopperimmediately， and shake the solution to react. 3) After the reaction solution is cooled again at 0 to 5 °℃ for 5 minutes， add 5 mL of 150 g/Lpotassium iodide solution and shake vigorously. 4) Open the reaction solution into a 200 mL tall beaker， rinse the inside of the Erlenmeyer flaskand the stopper with 100 mL of pure water， and collect the reaction solution and the rinsesolution. 5) Titrate with 0.1 mol /L Sodium thiosulfate solution. 7.Calculation Factor=EP1xC1xFA/S EP1 Titration amount(mL) C1 Concentration conversion coefficient =0.2 FA Factor of 0.1 mol/L sodium thiosulfate solution = 1.0430 S Sample size =5 (mL) 8. Example 一Parameter一 Auto Int. End Point No. EP Stop End Sense Auto Gain Data Sampling Standard Max Volume 30(mL) Ctl. Speed Mode Standard Channel/Unit(Ctrl.) Ch1，mV Other Control Standard Channel/Unit(Ref.) Off Auto Int. Mode Standard pH Polarity Standard Stir. speed 4 Titr. Type Check No Check Direction Auto Wait time 0(s) Dose Mode None (The above condition is an example. The setting condition depends on the model.) -Example of titration curve 一 -Measurement resultsS一 Titration (mL) Factor 1 24.1015 1.0055 2 24.0938 1.0052 3 24.0993 1.0054 Average 一 1.00537 一 0.00015 RSD (%) 一 0.015 9. Notes When the titration volume is large， as in this measurement， titration time can be shortened bysetting the titrator to inject a fixed amount of titrant. 10. Reference ·ASTM D1159 Standard Test Method for Bromine Numbers of Petroleum Distillates andCommercial Aliphatic Olefins by Electrometric Titration ·ASTM D5776 Standard Test Method for Bromine Index of Aromatic Hydrocarbons byElectrometric Titration 京都电子工业株式会社-可睦电子(上海)商贸有限公司电话：021-54488867 电邮： kemu-kem@163.com