Teknologi dan Rekayasa Kompetensi Keahlian Analisis Kimia

Qualitative Inorganic Analysis By : Tedi Hadiana SMK Negeri 13 Bandung

Preliminary Test By : Tedi Hadiana SMK Negeri 13 Bandung

Preliminary Test For Solid Samples Generally test Appearance : Observe whether it is  crystalline or powder  magnetic  possesses any characteristic odour or colour Flame test Test with H 2 SO 4 (dilute and concentrated) Test with NaOH Test with KHSO 4 Solubility test

Chemical substance type Chemical Substance Solid Liquid Gas Crystalline Powder

Difference of Crystalline and Powder type POWDERCRYSTALLINE Very small particle size (fine grained) Large particle size than powder Memiliki kilap saat terkena cahaya Tidak memiliki kilap Ex. : CaCO 3, MnSO 4, Amyllum, etc Ex. : NaCl, Na 2 S 2 O 3, CuSO 4, K 2 Cr 2 O 7, etc

Colour Chemical Compound RedAs 2 S 2, HgI 2, Sb 2 S 3, Cu 2 O, K 3 [Fe(CN) 6 ], Fe(SCN) 3, etc Orange-redK 2 Cr 2 O 7 Reddish-purpleKMnO 4 PinkHydrated salts of Manganese and of Cobalt YellowK 2 CrO 4, K 4 [Fe(CN) 6 ], CdS, Fe(III), PbI 2, etc GreenCr(III), Fe(II), Ni(II), Cr 2 O 3, K 2 MnO 4, etc BlueCu(II), anhydrous cobalt salts BrownFe 2 O 3, Fe(OH) 3, MnO 2, etc BlackPbS, FeS, NiS, CuS, HgS, C, etc Some of commonly occurring coloured compound are listed below:

Colour

Hygroscopis Properties 1.Some chemical substance can easily catch water from air  Chemical substance wet looks 2.Generally, chloride salt have hygroscopis properties. Example : CaCl 2, MgCl 2, CoCl 2, FeCl 3, MnCl 2, etc 3.Other example : NaOH, KOH, etc

Odour OdorsChemical Compound Ammonia smellAmmonium salt Rotten eggs smellSulfide salt Nitrous smellNitrate or nitrite salt Vinegar smellAcetate salt Halogen smellHalide salt (Iodide, Bromide, Chloride) Some of commonly occurring odoured compound are listed below:

Flame Test A small quantity of substance + a little concentrated HCl and introduce a little of the substance on a clean platinum wire into the base of non luminous bunsen flame

Flame test The sodium flame masks that of other element, e.g. that of potasium. Mixture can be readily detected with the direct vision spectroscope. A less delicate method is to view the flame through two thickness of cobalt blue glass, the yellow colour due to sodium is masked or absorbed and the other colour are modified as listed in below :

Flame test NaSr K LiCu

Test with H 2 SO 4 ObservationInference Gas is odourless and produces turbidity when passed into Ba(OH) 2 CO 2 from carbonate or hydrogen carbonate Suffocating odour, turns filter paper moistened with acidified K 2 Cr 2 O 7 green SO 2 from sulphite Suffocating odour, turns filter paper moistened with acidified K 2 Cr 2 O 7 green and sulphur is deposited in the solution SO 2 and sulphur from thiosulphate Odour of rotten eggs, blackens filter paper moistened with lead acetate solution H 2 S from sulphide Odour of rotten eggs, blackens filter paper moistened with lead acetate solution and sulphur is deposited H 2 S and sulphur from polysulphide Odour of vinegar, blue litmus  red colourCH 3 COOH from acetate Test with dilute H 2 SO 4  produces Colourless Gas

Test with H 2 SO 4 ObservationInference Reddish brown gas, and turning starch-KI paper bluish black NO 2 from nitrite Yellowish green gas, suffocating odour, reddens and then bleaches blue litmus paper, turn starch-KI paper blue Cl 2 from hypochlorite Test with dilute H 2 SO 4  produces Colour Gas

Test with H 2 SO 4 ObservationInference Gas is odourless and produces turbidity when passed into Ba(OH) 2 CO 2 from oxalate Gas is Pungent odour, white furnes in contact with concentrated NH 3 solution HCl from Chloride “Oily” appearance of tube in cold; On warming pungent gas evolved which corrodes the glass; if moistened glass rod introduced into the vapour gelatinous presipitate is deposited HF from fluoride Odour of rotten eggs, blackens filter paper moistened with lead acetate solution H 2 S from sulphide Odour of rotten eggs, blackens filter paper moistened with lead acetate solution and sulphur is deposited H 2 S and sulphur from polysulphide Odour of vinegar, blue litmus  red colourCH 3 COOH from acetate Test with concentrated H 2 SO 4  produces Colourless Gas

Test with H 2 SO 4 ObservationInference Reddish colour gas, pungent odour and and turning starch-KI paper blue HBr and Br2 from bromide Violet vapours gas, accompanied by pungent acid fumes and turning starch paper blue HI and I2 from iodide Brown gas from NO 2, accompanied by pungent acid fumes, and turning starch-KI paper bluish black HNO 2 and NO 2 from nitrate Yellow gas evolved in the cold with characteristic odour; explosion or crackling noise on warm ClO 2 from chlorate Test with concentrated H 2 SO 4  produces Colour Gas

Test With NaOH Place a few of sample upon watch glass The function this test  identification of ammonium ions Place red litmus paper under watch glass Add a small NaOH solution and watch glass with red litmus paper cover immediately If NH 4 + is present red litmus  blue litmus

Test With KHSO 4 Place a few of sample upon mortar The function this test  identification of acetate ions Shatter KHSO 4 with sample Add a small KHSO 4 solid Vinegar smell (acetate present)

SolubilityTest  Many substance are soluble in water on in acid. If such information is not available, the following procedure should be adapted  Use small quantities of the powdered solid and examine the solubility in the following solvents in the order given :  Water,  dilute,  hydrochloric acid,  concentrated hydrochloric acid,  dilute nitric acid,  concentrated nitric acid,  aqua regia

SolubilityTest  Try the solubility first in the cold and then on warming  If the substance dissolve in water, proceed immediately to test for metal ions.  If the use of dilute hydrochloric acid results in the formation of a precipitate, this may consist of metal of group 1 (the precipitate may either be filtrate off and examined for this group or else the original substance may be dissolved in dilute nitric acid)