The specific gravities of blende (3.9 to 4.2) and siderite (3.7 to 3.9) are almost identical, and they may not be separated by any method
The co-occurrence of the sulphides of zinc and iron is frequent; blende and pyrite, or marcasite, are found together in important ore bodies which are
Apparatus, Reagents.—Apparatus as before. For the standard solution, pure HgCl2 is required. For analysis the student may take further portions of the materials used in
Apparatus, Reagents, etc.—The same as in the last analysis, except that the chromate is not required. For analysis the student may take a solution prepared
Apparatus, Reagents.—The usual apparatus. For the standard solution, ammonium molybdate is required [(NH4)2MoO4], or by a simple calculation the heptamolybdate (NH4)6Mo7O24,4H2O which is non-deliquescent, or
Apparatus, Reagents.—The usual apparatus. For the preparation of the standard solution pure K4FeC6N6 (free from K6Fe2C12N12) is used, and pure ZnO is employed for checking the standard.
VOLUMETRIC ESTIMATION OF MANGANESE BY POTASSIUM PERMANGANATE. (Volhard’s Method) Aparatus. Reagents.—The usual apparatus. For the standard solution K2Mn2O8 is required. Zinc oxide free from Mn
VOLUMETRIC ESTIMATION OF ARSENIC (Pearce’s Method) Apparatus, Reagents —The usual apparatus. For precipitation E. AgNO3 may be used. For the standard solution NH4CNS is used, and
THE ESTIMATION OF IRON BY STANDARD SOLUTION OF POTASSIUM PERMANGANATE (Marguerite’s Method). Apparatus, Reagents.—The usual volumetric apparatus, For standardising the solution soft iron wire such
THE ESTIMATION OF IRON BY STANDARD POTASSIUM BICHROMATE SOLUTION (Penny’s Method). Apparatus, Reagents.—For the preparation of the standard solution pure K2Cr2O7 is required, also the iron