摘要
在马弗炉(200℃)灼烧至草酸全部挥发,滴加(1+1)盐酸,使刚果红试纸由红变蓝色(或调节pH到4左右),除去二氧化碳。加入钡镁混合液,沉淀6h(或放置过夜)。加入(1+1)氨水调节pH值约为8—9,加入10mL氨-氯化铵缓冲溶液,2滴铬黑T指示剂,用EDTA标准溶液滴定SO2-4含量。
The oxalic acid was cauterize in the muffle at 200℃ until fully volatilized. The solution pH was adjusted with drop （1＋1） hydrochloric acid （the congo red test paper change color from red to blue） to about 4 to remove carbon dioxide. SO4^2- in the solution was precipitated with mixted solution of barium and magnesium for 6 hours or over night. The solution pH was adjusted with 1＋1 ammonia to about 8-9, and 10mL of NH3-NH4Cl buffer solution and 2 drops of chromium black T indicator were added. The residual barium was titrated with EDTA standard solution, and the content of SO4^2- was calculated.
出处
《光谱实验室》
CAS
CSCD
2005年第4期749-752,共4页
Chinese Journal of Spectroscopy Laboratory
关键词
草酸
EDTA滴定
硫酸根
Oxalic Acid, EDTA Titration, Sulfurate
