A manual of practical chemistry for public health students : especially arranged for those studying for the D.P.H / by A.W. Stewart.

  • Alfred Walter Stewart
Date:
1913
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Licence: In copyright

Credit: A manual of practical chemistry for public health students : especially arranged for those studying for the D.P.H / by A.W. Stewart. Source: Wellcome Collection.

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    Cl. Add sodium carbonate solution, filter, acidify filtrate with nitric acid, then add silver nitrate. A white curdy precipitate is formed, soluble in ammonia. 2 HgCl2 + Na2C03 = HgC03 ‘HgO + 2 NaCl NaCl + AgN03 = AgCl + NaNOs (2) Ferrous Sulphate. FeS04. Fe. (a) Potassium ferricyanide gives a deep blue precipitate known as Turnbull’s blue. 3 FeS04 + 2 K3 Fe (CN)6=Fe3 [Fe(CN)6] 2+3 K2S04 (b) Solution of ammonia gives a whitish precipi- tate which turns to dirty green and then brown. FeS04 + 2 NH4OH = Fe(OH)2 + (NHJ2 S04 S04. Acidify with dilute HC1, add barium chloride. A white precipitate is formed, insoluble in 3.11 acids BaCl2 + FeS04 = BaS04 + FeCl2 (3) Carbolic Acid. C(;H50H. (a) Ferric chloride gives a violet colour. (b) Bromine water gives a yellowish-white precipitate of tribromophenol. C6H5OH + 3 Br2 = C,H2Br3OH + 3 HBr (c) Add a drop of nitric acid, warm, dilute with water, then add ammonia. A yellow colour due to ammonium picrate is obtained. CcH5OH + 3 HN03 = C6H2OH (N02)3 + 3 H20 \a1n7non. picrate~\ C6Ho0H(N0o)3 + NH4OH = C6Ho0NH4(N0o)3 + h2o (4) Hydrogen Peroxide. H202. (a) Add a few drops of potassium bichromate and a little dilute sulphuric acid, then 10 c.c. of ether. Shake and allow to stand. A blue layer settles out. (b) Add 2 c.c. of dilute permanganate solution and acidify with dilute sulphuric acid. Oxygen is evolved and the colour of the permanganate is discharged. 5 H2Q2 + 3 H2S04 + 2 KMn04 =