Qualitative Chemical Analysis

Lecture:

Course code of lecture: GYTK22A-301

Head of subject (lecture): Dr. Márta Palkó

Type of subject: compulsory

Credit value: 3

Number of contact hours (per week): 2

Form of mid-year report: -

Assessment/examination form: colloquium

Site in curriculum: Semester 2

Subject prerequisite(s) (lecture): General Chemistry lecture (GYTK22A-201), Qualitative Chemical analysis practice (GYTK22A-302)

Practice:

Course code of practice: GYTK22A-302

Head of subject (practice): Prof. Dr. István Szatmári

Instructors involved in subject teaching (practice): Dr. Bálint Lőrinczi, Dr. Attila Márió Remete

Type of subject: compulsory

Credit value: 3

Number of contact hours (per week): 4

Form of mid-year report: completion of 3 written MTOs

Assessment/examination form: term mark

Site in curriculum: Semester 2

Concepts and aims:
The aim of the qualitative chemical analysis is the introduction to the methods for the detection and separation of the most important elements and groups. The students acquire the rules of the laboratory works, management of the simple operations, descriptions of the reactions by equations and knowledge of the analytical thinking. The subject has close connection with the general chemistry, physical chemistry, quantitative analytical chemistry, inorganic chemistry, pharmaceutical chemistry and drug analysis. The subject is necessary for the qualification of drug compounds, according to the pharmacopoeia and for detection of impurities.

Prescribed outside practice: no

The main matter of the lectures:

Ions. Classification of reactions: redox reactions. Oxidation number, oxidation state. Oxidation and reduction, acid-base reactions. Reactions involving precipitation. Complex-formation reaction. Complex cations. Complex anions. Neutral complexes. Chelates. Reaction sensitivity, Reaction specificity

Groups of cations
Group 1: Hydrogen sulphide group. Group reaction. Reagents. General characterization of group 1.
Group 1A (hydrochloric acid sub-group) Silver(I), reaction with hydrogen sulphide, chlorides, bromides and iodides, alkali hydroxides, ammonia, chromates. Lead(II), reaction with hydrogen sulphide, chlorides, iodides, sulphates, alkali hydroxides or ammonia, chromates. Mercury(I), reaction with sulphides, chlorides, ammonia, alkali hydroxides, iodides, metallic copper.
Group 1B (copper sub-group) Mercury(II), reaction with sulphides, ammonia, alkali hydroxides, tin(II) chloride, iodides, metallic copper. Copper(II), reaction with sulphides, ammonia, alkali hydroxides, hexacyanoferrate(II), cyanides, iodides, metallic iron or zinc, flame colouration. Bismuth, reaction with sulphides, alkali hydroxides or ammonia, water, hydrolysis, tetrahydroxostannate(II), iodides. Cadmium, reaction with sulphides, alkali hydroxides, ammonia, cyanides.
Simple analysis of cation group 1.
Group 2 (arsenic group)
Group reaction. Reagents. Arsenite arsenic(III), reaction with sulphides, silver ions, iodine, Marsh reaction, Bettendorf reaction, Gutzeit test, Sanger-Black test, heating test. Arsenate arsenic(V), reaction with sulphides, silver ions, Marsh, Bettendorf, Sanger-Black and Gutzeit reactions, magnesia mixture. Antimony(III), reaction with sulphides, water, hydrolysis, alkali hydroxides or ammonia, metallic zinc or iron, Marsh, Sanger-Black and Gutzeit test. Antimony(V), reaction with sulphides, iodides. Tin(II), reaction with sulphides, mercury(II), alkali hydroxides, metallic zinc, luminescence test. Tin(IV), reaction sulphides, alkali hydroxides, metallic zinc, metallic iron.
Simple analysis of cation group 2.
Group 3 (ammonium sulphide group)
Group reaction. Reagents. Cobalt(II), reaction with ammonium sulphide, alkali hydroxides, ammonia, cyanides, thiocyanates, nitrites. Borax-bead test. Nickel(II), reaction with ammonium sulphide, ammonia, alkali hydroxides, cyanides, dimethylglyoxime, Iron(II), reaction with ammonium sulphide, alkali hydroxides or ammonia, hexacyanoferrate(III), a, a-dipyridyl, permanganate. Iron(III), reaction with ammonium sulphide, hydrogen sulphide, ammonia or alkali hydroxides, sodium acetate, hexacyanoferrate(II), thiocyanate, iodides. Chromium(III), reaction with ammonium sulphide, ammonia, alkali hydroxides, hydrogenperoxide. Oxidation to chromate in melt phase. Chromate, reaction with sulphides, ethanol, silver ion, barium ions, peroxichromate reaction. Aluminium(III), reaction with ammonium sulphide, ammonia, alkali hydroxides, alizarinsulphonate, Thénard-blue test. Zinc(II), reaction with ammonium sulphide, ammonia, alkali hydroxide, hexacyanoferrate(II), Rinmann-green test. Mangan(II), reaction with ammonium sulphide, ammonia or alkali hydroxides. Oxidation to permanganate with lead(IV). Oxidation to permanganate with persulphate. Oxidation in the melt phase. Permanganate, reaction with sulphides, peroxides, ethanol.
Simple analysis of cation group 3.
Group 4, alkaline earth (ammonium carbonate) group
Group reaction. Reagents. Calcium(II), reaction with ammonium carbonate and carbonates, sulphate, oxalate, phosphates, hexacyanoferrate(II), chromate. Visible spectrum. Strontium(II), reaction with ammonium carbonate and carbonates, sulphates, lime water, oxalate, phosphates, visible spectrum, flame colouration. Barium(II), reaction with ammonium carbonate and carbonates, sulphates, calcium or strontium sulphate, oxalates, phosphates, chromate or dichromate. Visible spectrum, flame colouration.
Simple analysis of cation group 4.
Group 5, magnesium and alkali metal group (soluble group)
Group reaction. Magnesium(II), reaction with ammonia, alkali hydroxides, ammonium carbonate, phosphates, quinalizarine. Sodium(I), reaction with antimonate, zinc uranylacetate. Visible spectrum, flame coloration. Potassium(I), reaction with tartaric acid, hexanitrocobaltate(III), perchloric acid, tetraphenylboron. Visible specturm, flame colouration. Ammonium reaction with tartaric acid, hexanitrocobaltate(III), tetraphenylboron, strong bases. Nessler reaction. Lithium(I), reaction with ammonium carbonate, phosphates. Visible spectrum flame colouration.
Simple analysis of cation group 5.

Groups of anions
Group 1
Carbonate, reaction with acids, hydrolysis (phenolphthalein), magnesium sulphate Hydrogencarbonate, reaction with acids, hydrolysis, magnesium ions. Sulphite, reaction with acids, barium ions, silver ions, iodine. Thiosulphate, reaction with acids, silves ions, iodine. Heating in flame. Sulphide, reaction with acides, nitroprusside, Hepar-reaction. Polysulphide, reaction with acids. Silicate, reaction with dilute acids, molybdate. Tetrafluoride test. Hypochlorite, formation and reaction with acids.
Group 2
Group reaction. Sulphate, reaction with barium ions, lead ions. Hepar reaction. Water-insoluble sulphates. Phosphate, reaction with barium ions, silver ions, magnesia mixture, molybdates. Borate, reaction with barium ions, silver ions. Turmeric paper reaction. Flame coloration. Fluoride, reaction with barium, calcium and silver ions, sulphuric acids, thiocyanates. Tetrafluoride test. Bromate, reaction with barium ions, silver ions, bromides, concd. hydrochloric acid, metallic zinc. Iodate, reaction with barium ions, silver ions, iodides, concd. hydrochlorid acid, metallic zinc.
Group 3
Group reaction. Chloride, reaction with silver ions, Chromyl chloride reaction, Berg reaction, oxidative agents. Bromide, reaction with silver ions, chlorine water, permanganate. Iodide, reaction with silver ions, chlorine water, iron(III) ions, oxidants. Cyanide, reaction with silver ions, hexacyanoferrate(II) reaction, acids (HCl), iodine or bromine. Thiocyanate, reaction with silver ions, iron(III) ions.
Group 4
Group reaction. Nitrate. Brown-ring test. Reduction with metallic zinc in alkaline medium. Nitrite, reaction with strong acids, iron(II) ions, Griess-Ilosvay reaction, urea, permanganate oxidation, iodide, metallic zinc. Acetate, reaction with strong acids, iron(III) ions. Esterification. Decarboxylation with calcium oxide. Chlorate, reaction with strong acids, disproportionation by heating, concd. sulphuric acid, iodides, metallic zinc. Perchlorate, reaction with iodides, metallic zinc, potassium ions. Methylene blue reaction.

Total analysis of solids for cations and anions: physical appearance, colour, preliminary tests, heating, flame colouration, preparation of solution, analysis for cations and anions.
Identification of anions in mixtures chloride, bromide and iodide. Chloride and iodide. Bromide, iodide and nitrate. Nitrite and nitrate.

Practicals: follow the topic of the lecture

University note:
G. Stájer, Qualitative Inorganic Analysis, Institute of Pharmaceutical Chemistry, Szeged, 1988