1、碱标准溶液浓度标定摘要： 酸碱标准溶液是采用间接法配制的，其浓度必须用基准物质来标定。也可根据酸碱溶液中已标出其中一种溶液的浓度，然后按它们的体积比V（NaOH）/V（HCl）来计算出另一种标准溶液的浓度。关键词：碱标准溶液 浓度标定 邻苯二甲酸氢钾 NaOH 标准溶液引言NaOH 标准溶液可用邻苯二甲酸氢钾（KHC 8H4O4，M=204.2） ，以酚酞为指示剂进行标定，它易提纯，易干燥，无结晶水，不吸潮，摩尔质量大，是一种较好的基准物质。实验部分1.1 主要原料 邻苯二甲酸氢钾（天津金汇太亚化学试剂有限公司 ） 0.40.6g， 蒸馏水（郑州市金水区喜星纯水厂） ， 酚酞指示剂（山东泰安新
2、泰峰磊化工有限公司） ， NaOH 标准溶液（实验室自配） 1.2 主要设备碱式滴定管（50ml） 锥形瓶（250ml） 称量瓶 洗瓶 分析天平1.3 反应机理 酸碱标准溶液是采用间接法配制的，其浓度必须用基准物质来标定，标定碱的基准物常用邻苯二甲酸氢鉀或草酸。与 NaOH 反应：KHC8H4O4 +NaOH KNaC8H4O4 + H2O1 实验分析与讨论2.1用减量法准确称取邻苯二甲酸氢 0.40.6g 于锥形瓶中，同时称取三份，各加 50ml 蒸馏水溶解，必要时可小火温热溶解。冷却后加入 2 滴酚酞指示剂，用欲标定的 NaOH 标准溶液滴定，近终点时要逐逐滴或半滴加入，直至被滴定溶液由无
3、色至微红色半分钟不褪，即为终点。2.2记录项目 I II III称量瓶+邻苯二甲酸氢钾（前）称量瓶+邻苯二甲酸氢钾（后）邻苯二甲酸氢钾质量13.9953g13.4295g0.5658g13.4295g13.0270g0.4025g13.0270g12.5567g0.4703gNaOH 最终读数NaOH 最初读数28.01ml0.41ml21.00ml0.10ml23.02ml0.12mlV（NaOH） 27.60ml 20.90ml 22.90mlc（NaOH） 0.1005mol/L 0.0944moi/L 0.1007mol/Lc（ NaOH） 0.0985mol/L个别测定的平均偏差 +
4、0.0020 -0.0041 +0.0022相对平均偏差 2.8%2.3 结论（1）c （NaOH）= 1000*m（KHC 8H4O4）/M(KHC 8H4O4)* V（NaOH）C(HCI)=0.0895mol/L（2）由于在配制溶液过程中读数存在偏差，滴定过程中，读数存在偏差，造成相对平均偏差较大。标定溶液浓度时称量不需要准确测量 KHC8H4O4 的质量，因为公式中 KHC8H4O4 的质量是实际称得的质量，称量在 0.50000.0500 范围内都是允许的。3 参考文献：1. 高烽 科技论文写作规范和写作技巧 100 例。北京：防空工业出版社，20052. 曾剑芬（译）科技论文写作与
5、发表教程。 北京：电子工业出版社，20063. 展海军、李建伟 无机及分析化学实验 郑州：郑州大学出版社，20074. 南京大学化学实验教学组编。大学化学实验 北京：高等教育出版社，19995. 沈君朴主编。实验无机化学。第二版 天津：天津大学出版社，1992 英语翻译：Alkali concentration of standard solution calibrationAbstract: the standard solution is to use the indirect method in acid and alkali, its concentration must be cal
6、ibration with standard substance. Can also be marked according to the acid and alkali solution has been one of the concentration of the solution, and then press the volume V(NaOH)/V(HCl)to calculate the concentration of a solution of another standard.Keywords:alkali concentration of standard solutio
7、n calibration potassium hydrogen phthalate NaOH standard solutionThe introductionNaOH standard solution available potassium hydrogen phthalate (KHC8H4O4, M = 204.2), with phenolphthalein as indicator for calibration, easy purification, it is easy to dry, no crystallization water, moisture absorption
8、, molecular weight, is a good reference materialThe experiment part1.1 the main raw materialPotassium hydrogen phthalate (tianjin jin hui chemical reagent co., LTD.) 0.4 0.6 g, distilled water (zhengzhou jinshui district xi star ChunShuiChang), phenolphthalein indicator (shandong taian xintai feng l
9、ei chemical co., LTD.), NaOH standard solution (lab)1.2 the main equipmentAlkali type buret (50 ml) conical flask (250 ml) weighing bottle washing bottle analytical balance1.3 the reaction mechanismStandard solution is to use the indirect method in acid and alkali, its concentration must be use stan
10、dard substance to calibration, calibration of alkali benchmark commonly used potassium hydrogen phthalate or oxalic acid. Reaction with NaOH: KHC 8H4O4 +NaOH KNaC8H4O4 + H2O1 the experimental analysis and discussion2.1By decrement method accurately said phthalic acid hydrogen 0.4-0.6 g in the conica
11、l flask, said three copies at the same time, each 50 ml distilled water dissolve, small HuoWen heat dissolved when necessary. Cooled add 2 drops of phenolphthalein indicator, used for calibration of NaOH standard solution titration, close to the end to chase one by one or half drops to join, until t
12、hey are titration solution from colorless to reddish half minutes do not fade, is the end.2.2Record the projectI II IIIWeighing bottle + potassium hydrogen phthalate (before)Weighing bottle + potassium hydrogen phthalate (back)The quality of phthalic acid potassium hydrogen13.9953g13.4295g0.5658g13.
13、4295g13.0270g0.4025g13.0270g12.5567g0.4703gNaOH final readingsNaOH initial readings28.01ml0.41ml21.00ml0.10ml23.02ml0.12mlV（NaOH） 27.60ml 20.90ml 22.90mlc（NaOH） 0.1005mol/L 0.0944moi/L 0.1007mol/Lc（NaOH） 0.0985mol/LAverage deviation of individual measurement+0.0020 -0.0041 +0.0022Average relative de
14、viation2.8%2.3 the conclusion(1) c (NaOH) = 1000 * m (KHC8H4O4) / m (KHC8H4O4) * V (NaOH)C (HC) = 0.0895 mol/L(2) there is a deviation due to the readings in the process of configuration solution, titration process, there exist deviations in readings, the average relative deviation is larger. Calibr
15、ation solution concentration when weighing KHC 8H4O4 quality does not need accurate measurement, because the quality is the actual formula KHC8H4O4 according to quality, weighing 0.5000 0.0500 range are allowed.Three references:1. Gao Feng writing norms and writing skills of scientific papers in 100
16、 cases. Beijing: defense industry press, 20052. Ceng Jianfen (eds) science and technology thesis writing and published tutorial. Beijing: electronic industry press, 20063. Show the navy, granular inorganic and analytical chemistry experiment in zhengzhou, zhengzhou university press, 20074. Nanjing university chemistry experiment teaching to compile. University chemistry experiment in Beijing: higher education press, 19995. Shen Junpiao editor. Inorganic chemistry experiment. The second edition of tianjin: tianjin university press, 1992
