钙羧酸(Calconcarboxylic acid)：3737-95-9
钙羧酸
1-(2-羟基-4-磺基-1-萘基偶氮)-2-羟基-3-萘甲酸;3-羟基-4-(2-羟基-4-磺基-1-萘基偶氮)萘-2-羧酸;钙试剂羧酸;钙试剂羧酸钠;钙羧酸钠;钙羧酸指示剂;钙羧酸指示剂(INDICATOR);钙红,钙指示剂,钙羧酸,3-羟基-4-[(2-羟基-4-磺基-1-萘基)偶氮]-2-萘羧酸,2-羟基-1-(2-羟基-4-磺基-1-萘基偶氮)-3-萘甲酸
Calconcarboxylic acid
2-Hydroxy[(2-hydroxy-4-sulpho-1-naphthalene)azo]naphthalene-3-carboxylicacid;2-naphthalenecarboxylicacid,3-hydroxy-4-[(2-hydroxy-4-sulfo-1-naphthalenyl)az;3-HYDROXY-4-(2-HYDROXY-4-SULFO-1-NAPHTHYLAZO)-2-NAPHTHALENECARBOXYLICACID;3-HYDROXY-4-(2-HYDROXY-4-SULFO-1-NAPHTHYLAZO)NAPHTHALENE-2-CARBOXYLICACID;2-HYDROXY-1-(2'-HYDROXY-4'-SULFO-1'-NAPHTHYLAZO)-3-NAPHTHOICACID
3737-95-9
223-117-0
C21H14N2O7S
438.41
1.60±0.1 g/cm3(Predicted)
300 °C(lit.)
-0.50±0.40(Predicted)
slightly soluble
Stable. Incompatible with strong oxidizing agents.
Very dark purple to black Powder
Xi
36/37/38
29270000
26-36-37/39
钙指示剂又称“钙-羧酸”，学名“2-羟基-1-(2-羟基-4-磺酸基-1-萘偶氮)-3-萘甲酸”，一种双邻羟基偶氮类显色剂，紫红色或褐色结晶性粉末。易溶于氢氧化钠和氨水，微溶于水和醇，其水和醇的溶液不稳定。在水溶液中pH值为7.3～13.7范围内呈蓝色，能作钙、镁、锌、镉、锰等离子络合滴定的指示剂。与钙离子形成的络合物呈红色，变色敏锐，且非常明显，故常用于钙、镁混合体系中测定钙。若溶液中存在有铁、铝等离子时，会封闭指示剂，可用氰化钾(KCN)及三乙醇胺联合加以掩蔽。
