Methodical instruction for students of (medical faculty)
LESSON 3 (6 hours)
Theme: 1. Introduction of biogenic elements. (3 hours).
2. Complex compound in biological systems (3 hours).
Aim: To study properties and biological function of s-, p-, and d-elements. To be able to determine of temporally hardness of water by a acid-base titration, and to determine of total hardness of water by a chelatometry.
Professional motivation: In living organism they’re over 75 chemical elements. Six from them is a carbon, hydrogen, nitrogen, oxygen, phosphorus and sulphur, which is called oligoelements are basis for carbohydrates, lipids, proteins, nucleic acids. About 20 chemical elements are vitally important for human.
Derivative aminopolicarboxylic acids – complexones have been used in volumetric analysis for determination of metal ions concentration in solution. For example, Trilonum B with alkaline-earth metal was made complex, that used for quantitative determination their. Also Trilonium B has been used for determination of total hardness of water. Trilonum has been used at atherosclerosis and arthritises. Calcium-disodium etelrndiaminotitraacetic acid (EDTA), which is called calcium tetracene is used at venenatings by heavy metals or rare-earth and radio nuclides such as plutonium, ittrium, cerium, zirconium, and el.
Basic level
1. Concept about complex and inner-complex compounds. (Secondary school course of chemistry).
Students’ practical Activities (900-1200)
I. Theme 1. Introduction of biogenic elements chemistry.
Work 1. Hydrolysis of salts of sodium and potassium.
Materials. 0.5 % sodium carbonate solution, sodium sulfate solution, sulfate potassium, phenolphthalein solution.
Protocol. Add in three test tube:
3-4 drops of waters solutions of such salts:
in first: sodium carbonate solution,
in second: sodium sulfate solution,
in third sulfate potassium. Add 1 drop of phenolphthalein solution in all test tubes. And observe change color of solutions.
Work 2. Qualitative reactions on cation of Са2+.
Materials. 0.5 % calcium chloride solution, solution.
Protocol. Add in test tube
2 drops of calcium chloride solution
2 drops of ammonium oxalate solution.
White color crystals of calcium oxalate is formed.
Work 3. Qualitative reactions on cation Fe2+ with a potassium hexacyanoferrate (K3[Fe(CN)6])
M a t e r i a l s: 2% solution of iron sulfate, 0,01 % solution of potassium hexacyanoferrate K3 [Fe(CN)6])
Protocol. Add in a test tube:
2-3 drops 2% solution of iron sulfate
2 drops to solution of К3Fe(СN)6.
Work 4. Qualitative reactions on cation Fe3+ with a potassium hexacyanoferrate (K4[Fe(CN)6])
M a t e r i a l s: 2% solution of iron chlorate, 0,01 % solution of potassium hexacyanoferrate K3 [Fe(CN)6])
Protocol. Add in a test tube:
2-3 drops 2% solution of iron chlorate
2 drops to solution of К4Fe(СN)6.
Work 5. Oxidation reaction iron (П) salt by potassium permanganate.
M a t e r i a l s: 2% solution of iron sulfate, 0,01 % solution of potassium hexacyanoferrate K4[Fe(CN)6])
Protocol. Add in a test tube:
2-3 drops 2 % solution of iron sulfate
1 drop of sulfate acid
1 drop of solution of potassium permanganate. Solution is mixed and add 2 drops to solution of К4Fe(СN)6.
Work 6. Determination of phosphorus in water and in biological fluids.
M a t e r i a l s: tape water, 2 % solution of ammonium molybdate, 2% solution of ascorbic acid, distilled water, synthetic detergent.
Protocol. Add in test tube 3-4 ml of tape water, add 2-3 drops 2 % solution of ammonium molybdate and 2-3 drops 2% solution of ascorbic acid. Mix the solution and leave for 15-20 min. If phosphates present in water, the solution becomes blue colour. The same test is carried out with distilled water.
Determination of phosphate on dishes after use of detergents.
Test tube wash by using synthetic detergent, and wash 3-4 times with tape water . In test tube add 4 ml of distilled water determine phosphate by the method given above.
Work 7. Determination of sulfate in water.
M a t e r i a l s: tape water, 10% solution of barium chloride.
Protocol. In test tube add 5 ml of tape water and add 3 drops 10% solution of barium chloride.
Sulfate content :
before 5 mg/l – no turbidity;
5 – 10 mg/l – some cloudy;
10 -100 mg/l – some cloudy that form immediately;
100 – 500 mg/l – a strong turbidity.
Work 8. Determination of iron in water.
M a t e r i a l s: tape water, HNO3 conc., 5% hydrogen peroxide, 20 % solution of potassium thiocyanate
Protocol. In test tube add 10 ml of tape water, add 1 drop of HNO3 conc., 3-4 drops 5% hydrogen peroxide and 0.5 ml 20 % solution of potassium thiocyanate (KSCN). The solution change colour to pink when the concentration of iron is nearly 0.1 mg/l. Greater concentration change colour to red.
II. Theme 2. Complex compound in biological systems.
Work 9. To determine total hardness of drinking water
The drinking water has a lot of different salt, for example calcium or magnesium chlorate. Amount grams of calcium and magnesium ions per liter of water are called total water hardness.
M a t e r i a l s: 0.1 mol/l Trilonum B solution, indicator solid eriochrome back T, ammonia buffer solution
P r o t o c o l. Fill burette with Trilonum B solution.
In flask add:
50 ml of sodium drinking (tap) water
10 ml of ammonia buffer solution
20-40 milligrams of the indicator solid eriochrome back T.
To titrate this solution by Trilonum B solution while colour of the indicator change from violet to blue.
C a l k u l a t i o n: the total hardness of water by the formula:
Seminar employment. (1230– 1400 hours).
Students’ Independent Study Program.
I. Theme 1. Introduction of biogenic elements chemistry.
1. Biogenic elements. macro- and oligoelementss.
2. Properties and biological role of some s-elements: potassium (K), sodium (Na), calcium (Са), magnesium (Мg).
3. Properties and biological role of some р-elements (fluorine, chlorine, bromine, iodine).
4. Properties and biological role of some d-elements (iron, manganese).
II. Theme 2. Complex compound in biological systems.
1. Complex compounds. They structure and biological role.
2. Basis of chelatometry.
3. Structure of complexones. Mechanism react Trilonum B with 2- and 3-charge metals.
4. Indicators of a chelatometry method and mechanism of change of their colour
5. Water hardness. The determination of water hardness.
6. Using Trilonum B and other complexes in medicine.
TEST EVALUATION AND SITUATIONAL TASKS.
1. Which method you can determine total hardness of water?
A. Acid-base titration
B. Chelatometry
C. Precipitaition
D. Oxidation – reduction
2. Manganese is:
A. s – element.
B. *d – element.
C. f – element.
D. p – element.
E. g – element.
3. Zinc is:
A. s – element.
B. *d – element.
C. f – element.
D. p – element.
E. g – element.
4. What is name of
A. Potassium cyanide cuprate(II).
B. Cupper potassium tetracyanate.
C. *Potassium tetracyanocuprate(II).
D. Potassium cyanatecuprate(II).
E. Potassium tetracuprate(II).
5. What element with calcium is present in bones?
A. Copper.
B. Cobalt.
C. Zinc.
D. Chlorine.
E. *Phosphorus.
6. 3,4 ml 0,0500 mol-eqa/l of Trilonum solution have been used for titration 50 mls of water. What total water hardness is?
7. 100 ml of solution have been prepared from
8. A water sample contains
9. 8,4 ml 0,0500 mol-eqa/l of Trilonum solution have been used for titration 50 mls of water. What total water hardness is?
10. 2.8 ml 0,0500 mol-eqa/l of Trilonum solution have been used for titration 50 mls of water. What total water hardness is?
Students should know:
– basic principles of chelatometry;
– influencing pH of medium to reaction EDTA with metals’ ions;
– application of complexones in medicine.
Students should be able to:
– determine total hardness of water by chelatometry.
Correct answers of test evaluations and situational tasks:
1. B
2. B
3. B
4. C
5. E
6. 3.400 mg-eqa/l;
7. 32.19 %.
8. 220 ppm CaCO3
9. 8.400 mg-eqa/l;
10. 2.800 mg-eqa/l;
References: 1. The abstract of the lecture.
2. Lawrence D. Didona. Analytical chemistry. – 2002:
3. John B. Russell. General chemistry.
4. http://intranet.tdmu.edu.ua/Student’s facilities/Practical classes materials/Department of Pharmaceutical Chemistry/medical chemistry/medical/1 course/English/03. Biogenic elements. Complex compounds
Methodical instruction has been worked out by:
Methodical instruction was discussed and adopted at the Department sitting
__________201 . Minute № ___
Methodical instruction was adopted and reviewed at the Department sitting
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