Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: REVIEW OF THE ANALYTICAL GROUPING OF THE METALS. GroupGroupGroupGroupGroupGroupVI.V.IV.III.II.I. A. B. A. B. AgPb AsFeZnBa MgKHg(ous)Hg(ic) Sb AlMnSrNaPbBi Sn CrNiCaNH4 Cu Co Cd VI. Thrown down as insoluble (ex. Pb) chlorides ?AgCl, Hg3Cl2, and PbCl2, ?all other chlorides being easily soluble in dilute HCl. V. Thrown down by H2S as sulphides from a solution acidified with HCl, the sulphides of the succeeding groups being soluble in dilute HCl. This group admits of two subdivisions. A. Sulphides?PbS, HgS, Bi2S3, CuS, CdS?insoluble in (NH4)2S2 or NaHO. B. Sulphides?As2S3, Sb2S3, SnS, and SnS2?soluble in (NH4)2S2 or NaHO. IV. After removing the two preceding groups the addition of NH4HO under proper conditions throws down Fe2(HO)6, Al2(HO)6, and Cr2(HO)6, with small quantities of Mn2(HO)6 when Mn is present. III. After removing the three preceding groups these are the only metals which form sulphides Add HCI. Precipitate Hg(ous) Pb Ag. Wash, boil with water, filt Insoluble Hg Ag. Wash, pour AmHO on the filter. Residue Black Hg. Filtrate Add HNO, White pp. Fi Ad (Compare p. 72.) Ig(ic) Pb Bi As(ousXic) Sb 3 Sn. 10, filter. Filtrate As Sb Sn. Add dil. HCl, filter, drain well, .I pp. in strong HCl, add water, er. Insol. ellow. nfirIn by itmann's Test orig. sol. Filtrate Sn Sb. Pour into Marsh's apparatus. escapes SB remains on the SbH, . the gas. Dissolve inHCl and test. (Compare p. 70-71.) f not, use Am.4Sa. nsoluble in water or alkaline solutions: ?ZnS, MnS, cCoS, NiS. These sulphides are not formed in pre- 'sence of HCl. II. Alkaline earth metals. Sulphides soluble in acids and more or less in water, and therefore cannot be precipitated. The group is divided into two parts. .