1. THEME: Solution. Coligative properties of biological liquids. Chemistry biogenic elements. Complex compound in biological systems LECTURE 1 associate prof. Dmukhalska Ye. B. prepared

2. PLAN 1. The main concepts of solutions 2. Types of solutions 3. Heat effect of a dissolution 4. Methods for expressing the concentration of a solution 5. Vapour pressure and Raoult’s law 6. Collogative properties

3. A solution is a homogeneous mixture of two or more substances whose composition can be varied within certain limits

4. The substances which is used for prepare the solutions are called components The components of a binary solution are solute and solvent. Solvent (water) is a component which is present in excess, in other words a solvent is a substance in which dissolution takes place. Solvent doesn’t change its physical state during reaction of dissolution. Solute (sodium chloride, sugar) is a component which is present in lesser quantity. Or solute is a substance that dissolves.

5. TYPES OF SOLUTION 1. Depending upon the total components present in the solution: a)Binary solution (two components) b) Ternary solution (three components) c)Quaternary solution (four components)…..etc. 2. Depending upon the ability of the some quantity of the solute in the solvent: 2. Depending upon the ability of the dissolution some quantity of the solute in the solvent: A saturated solution is one that is in equilibrium with excess undissolved solute, or would be in equilibrium if excess solute were present. An unsaturated solution is one in which the concentration of solute is less than its concentration in a saturated solution. A supersaturated solution is one in which the concentration of solute is greater than its concentration in a saturated solution.

6. 3. Depending upon the physical states of the solute and solvent, the solution can be classified into the following nine type:

7. 4. Depending upon the4. Depending upon the physical state Gas solution. Gaseous solutions have the structure that is typical of all gases. Air, the gaseous solution with which we come in closest contact, is composed primarily of N 2 (78 % by volume), O 2 (21 %), and Ar (1 %), with smaller concentrations of CO 2, H 2 O, Ne, He, and dozens of other substances at very low levels. Liquid solutions have the internal structure that is typical of pure liquids: closely spaced particles arranged with little order. Unlike a pure liquid, how­ever, a liquid solution is composed of different particles. Much of this chapter is devoted to the properties of liquid solutions, and special emphasis is given to aqueous solutions, in which the major component is water. Two kinds of solid solutions are common. The first, the substitutional solid solution, exhibits a crystal lattice that has structural regularity but in which there is a random occupancy of the lattice points by different species.

8. Concentration units of a solution The concentration of a solution may be defined as the amount of solute present in the solution. 1.Mass percentage or volume percentage The mass percentage of a component in a given solution is the mass of the com ponent per 100 g of the solution.

9. Mass concentration, titer (T) is number grams of solute (m) per one milliliter of solution (V). Or it is the ratio of the quantity grams of solute and volume solution:

10. 2. Molarity It is the number of moles of the solute dissolved per litre of the solution. It’s represented as M or C M C M = (М) = Moles of solute / Volume of solution in litres or C M = (М) = Mass of component A/ Molar mass of A *Volume of solution in litres The unit of molarity is mol/L, 1L = 1000 ml

11. 3. Molality It is the number of moles of the solute dissolved per 1000 g (or 1 kg) of the solvent. It’s denoted by m or Cm Cm = (m) = Moles of solute/Weight of solvent in kg or Cm = (m) = Moles of solute * 1000/Weight of solvent in gram The unit of Molality is m or mol/kg

12. 4. Normality: It is the number of gram equivalents of the solute dissolved per litre of the solution. It’s denoted by N or C N (N)= C N = Number of gram equivalents of solute/Volume of solution in litres or (N) = C N = Number of gram equivalents of solute *1000 / Volume of solution in ml Number of gram equivalents of solute = Mass of solute / Equivalent mass of solute

13. Relationship between Normality and Molarity of Solutions Normality = Molarity * Molar mass/Equivalent mass 5. Mole fraction - It’s denoted by X. 5. Mole fraction - is the number of moles of one substance (n a ) in the solution divided by the total number of moles of all kinds of substances in the solution. It’s denoted by X.

14. Raoult’s law for solutions containing non-volatile solutes Vapour pressure of the solution=Vapour pressure of the solvent in the solution If is the vapour pressure of the solvent over a solution containing non-volatile solute and is its mole fraction then according to Raolt’s law, or At a given temperature, the vapour pressure of a solution containing non-volatile solute is directly proportional to the mole fraction of the solvent

15. Collogative properties The dilute solutions of non-volatile solutes exhibit certain characteristic properties which don’t depend upon the nature of the solute but depend only on the number of particles of the solute, on the molar concentration of the solute. These are called colligative properties. Thus 1.Relative lowering in vapour pressure 2.Elevation in boiling point 3. Depression in freezing point 4. Osmotic pressure This mean that if two solutions contain equal number of solute particles of A and B then the two solutions will have same colligative properties

16. The relative lowering in vapour pressure of an ideal solution containing the non-volatile solute is equal to the mole fraction of the solute at a given temperature. where A is a solvent, B is a solute

17. Elevation in boiling point The boiling point of a liquid is the temperature at which its vapour pressure becomes equal to the atmospheric pressure. The boiling point of the solution is always higher than that of the pure solvent. The different in the boiling points of the solution and pure solvent is called the elevation in boiling point It has been found out experimentally that the elevation in the boiling point of a solution is proportional to the molality concentration of the solution where is called molal elevation constant or ebullioscopicconstant

18. Depression in freezing point The freezing point is the temperature a which the solid and the liquid states of the substance have the same vapour pressure. The freezing point of the solution is always lower than that of the pure solvent. where is the molal depression constant or molal cryoscopic constant

19. Determination of Molar mass

20. Osmotic pressure

22. OSMOSIS. It is the movement of water across a semi- permeable membrane from an area of high water potential (low solute concentration) to an area of low water potential (high solute concentration). It is a physical process in which a solvent moves, without input of energy, across a semi-permeable membrane (permeable to the solvent, but not the solute) separating two solutions of different concentrations water potentialsolutesolventwater potentialsolutesolventor Osmosis is the phenomenon of the flow of solvent through a semi-permeable membrane from pure solvent to the solution. Osmosis can also take place between the solutions of different concentrations. In such cases, the solvent molecules move from the solution of low solute concentration to that of higher solute concentration.

23. Osmotic pressure depends upon the molar concentration of solution Van’t Hoff observed that for dilute solutions, the osmotic pressure is given as:

24. Determination of Molar Mass from Osmotic Pressure Conditions for getting accurate value of molar mass 1.The solute must be non-volatile. 2.The solution must be dilute, concentration of the solute in the solution should not be more than 5 % 3.The solute should not undergo either dissociation or association in the solution.

25. If two solutions have same osmotic pressure are called isotonic solutions or isoosmotic solutions If a solution has more osmotic pressure than some other solutrion, it is called hypertonic On the other hand, a solution having less osmosis pressure than the other solution is called hypotonic To note that a 0,9% solution of sodium chlorine (known as saline water) is isotonic with human blood corpuscles. In this solution, the corpuscles neither swell nor shrink. Therefore, the medicines are mixed with saline water before being injected into the veins. 5% NaCl solution is hypertonic solution and when red blood cells are placed in this solution, water comes out of the cells and they shrink On the other hand, when red blood cells are placed in distilled water (hypotonic solution), water flows into the cells and they swell or burst

26. The effect of hypertonic and hypotonic solutions on animal cells.The effect of hypertonic and hypotonic solutions on animal cells. (а) Hypertonic solutions cause cells to shrink (crenation) - plasmolysis;(а) Hypertonic solutions cause cells to shrink (crenation) - plasmolysis; (b) hypotonic solutions cause cell rupture - hemolysis;(b) hypotonic solutions cause cell rupture - hemolysis; (c) isotonic solutions cause no changes in cell volume.(c) isotonic solutions cause no changes in cell volume.

27. (usually metallic),Coordination compounds are the compounds in which the central atom (usually metallic), is linked to а number of ions or neutral molecules by coordinate bonds i.е. by donation of lone pairs of electrons by these ions or neutral molecules to the central metal atom. nickel tetracarbonyl, [Ni(CO) 4 ] A coordination complex

28. Complex compounds А) Structure CuSO 4 + 4 NH 3 = [Cu (NH 3 ) 4 ] SO 4 [Cu (NH 3 ) 4 ] SO 4 Complex compound Cu 2+ - central atom NH 3 – ligand [Cu (NH 3 ) 4 ] 2+ - complex ion SO 4 2- -anion

29. Aqueous solutions that contain [Ni(H 2 O) 6 ] 2+, [Ni(NH 3 ) 6 ] 2+ and [Ni(en) 3 ] 2+ (from left to right). The two solutions on the right were prepared by adding ammonia and ethylenediamine, respectively, to aqueous nickel(II) nitrate.

30. Werner’s Theory Alfred Werner suggested in 1893 that metal ions exhibit what he called primary and secondary valences.Alfred Werner suggested in 1893 that metal ions exhibit what he called primary and secondary valences. –Primary valences were the oxidation number for the metal (+3 on the cobalt at the right). –Secondary valences were the coordination number, the number of atoms directly bonded to the metal (6 in the complex at the right).

31. The species formed by linking of а number of ions or molecules by co-ordinate bonds to the central metal atom (or ion) carries positive or negative charge, it is called a complex ion (coordination sphera). [Fe(СN) 6 ] 4-, [Cu(NH 3 ) 4 ] 2+, [Ag(CN) 2 ] -

32. Coordination sphere. The central atom and the ligands which are directly attached to it are enclosed in square brackets and are collectively termed as the coordination sphere.The central atom and the ligands which are directly attached to it are enclosed in square brackets and are collectively termed as the coordination sphere.

33. Metal-Ligand Bond This bond is formed between a Lewis acid and a Lewis base.This bond is formed between a Lewis acid and a Lewis base. –The ligands (Lewis bases) have nonbonding electrons. –The metal (Lewis acid) has empty orbitals.

34. Transition metals act as Lewis acidsTransition metals act as Lewis acids Form complexes/complex ionsForm complexes/complex ions Fe 3+ (aq) + 6CN - (aq)  [Fe(CN) 6 ] 3- (aq) Ni 2+ (aq) + 6NH 3 (aq)  [Ni(NH 3 ) 6 ] 2+ (aq) Complex with a net charge = complex ion Complexes have distinct properties Lewis acid Lewis baseComplex ion Lewis acid Lewis base Complex ion

35. Coordination compoundCoordination compound –Compound that contains 1 or more complexes –Example [Co(NH 3 ) 6 ]Cl 3[Co(NH 3 ) 6 ]Cl 3 [Cu(NH 3 ) 4 ][PtCl 4 ][Cu(NH 3 ) 4 ][PtCl 4 ] [Pt(NH 3 ) 2 Cl 2 ][Pt(NH 3 ) 2 Cl 2 ]

36. The donor atoms, molecules or anions, which donate а pair of electrons to the metal atom and form co-ordinate bond with it are called ligands.

37. Ligands classified according to the number of donor atomsclassified according to the number of donor atoms –Examples monodentate = 1monodentate = 1 bidentate = 2bidentate = 2 tetradentate = 4tetradentate = 4 hexadentate = 6hexadentate = 6 polydentate = 2 or more donor atomspolydentate = 2 or more donor atoms chelating agents

38. Ligands Monodentate ligandsMonodentate ligands –Examples: H 2 O, CN -, NH 3, NO 2 -, SCN -, OH -, X - (halides), CO, O 2-H 2 O, CN -, NH 3, NO 2 -, SCN -, OH -, X - (halides), CO, O 2- –Example Complexes [Co(NH 3 ) 6 ]Cl 3[Co(NH 3 ) 6 ]Cl 3 K 3 [Fe(SCN) 6 ]K 3 [Fe(SCN) 6 ]

39. Ligands BidentateBidentate –Examples oxalate ion = C 2 O 4 2-oxalate ion = C 2 O 4 2- ethylenediamine (en) = NH 2 CH 2 CH 2 NH 2ethylenediamine (en) = NH 2 CH 2 CH 2 NH 2 ortho-phenanthroline (o-phen)ortho-phenanthroline (o-phen) –Example Complexes [Co(en) 3 ] 3+[Co(en) 3 ] 3+ [Cr(C 2 O 4 ) 3 ] 3-[Cr(C 2 O 4 ) 3 ] 3- [Fe(NH 3 ) 4 (o-phen)] 3+[Fe(NH 3 ) 4 (o-phen)] 3+

40. Ligands oxalate ion ethylenediamine ortho-phenanthroline Donor Atoms: * ** * * * *

41. Ligands oxalate ion ethylenediamine O C M M N C H

42. Ligands

43. Chelation is a process in which a polydentate ligand bonds to a metal ion, forming a ring. The complex produced by this process is called a chelate, and the polydentate ligand is referred to as a chelating agent.Chelation is a process in which a polydentate ligand bonds to a metal ion, forming a ring. The complex produced by this process is called a chelate, and the polydentate ligand is referred to as a chelating agent. – ethylenediaminetetraacetate (EDTA) = (O 2 C-CH 2 ) 2 N-CH 2 -CH 2 -N(CH 2 -CO 2 ) 2 4- –Example Complexes [Ca(EDTA)] -2[Ca(EDTA)] -2 [Co(EDTA)] -1[Co(EDTA)] -1

44. EDTA Ligands * Donor Atoms * ** * **

45. EDTA Ligands C O N H M

46. Coordination number The number of ligand donor atoms that surround a central metal ion in a complex is called the coordination number of the metalThe number of ligand donor atoms that surround a central metal ion in a complex is called the coordination number of the metal Originally, a complex implied a reversible association of molecules, atoms, or ions through weak chemical bonds.Originally, a complex implied a reversible association of molecules, atoms, or ions through weak chemical bonds. [Ag(СN) 2 ] -, [Cu(NН 3 ) 4 ] 2+ and [Cr(Н 2 О) 6 ] 3+[Ag(СN) 2 ] -, [Cu(NН 3 ) 4 ] 2+ and [Cr(Н 2 О) 6 ] 3+

47. Common Geometries of Complexes Linear Coordination Number Geometry 2 Example: [Ag(NH 3 ) 2 ] +

48. Common Geometries of Complexes Coordination Number Geometry 4 tetrahedral square planar Example: [Ni(CN) 4 ] 2- Examples: [Zn(NH 3 ) 4 ] 2+, [FeCl 4 ] -

49. Common Geometries of Complexes Coordination Number Geometry 6 octahedral Examples: [Co(CN) 6 ] 3-, [Fe(en) 3 ] 3+

50. Coordination Number Geometry 8 Dodecahedron Cube Hexagonal bipyramid

52. Charge on the complex ion. The charge carried by а complex ion is the algebraic sum of the charges carried by central metal ion and the ligands coordinated to the central metal ion.The charge carried by а complex ion is the algebraic sum of the charges carried by central metal ion and the ligands coordinated to the central metal ion. [Ag (CN) 2 ]- [Ag (CN) 2 ]- [Cu (NH 3 ) 4 ] 2+ [Cu (NH 3 ) 4 ] 2+

53. [Fe(CN) 6 ] 3- Complex charge = sum of charges on the metal and the ligands +3 6(-1)

54. [Co(NH 3 ) 6 ]Cl 2 Neutral charge of coordination compound = sum of charges on metal, ligands, and counterbalancing ions neutral compound +2+2 6(0) 2(-1)

55. Oxidation number or oxidation state. It is а number that represents an electric charge which an atom or ion actually has or appears to have when combined with other atoms, oxidation number of copper in [Cu(NH 3 ) 4 ] 2+ is +2 but coordination number is 4. oxidation number of Fe in [Fe(СN) 6 ] 3- is + 3 but the coordination number is 6. (i) [Cu (NН З ) 4 ]SO 4. (ii) Fe in [Fe (СN) 6 ] 3- (iii)К 3 [Fe(С 2 О 4 ) 3 ]. (iv) [Ni(CO) 4 ].

56. [Co(NH 3 ) 6 ]Cl 2 Neutral charge of coordination compound = sum of charges on metal, ligands, and counterbalancing ions neutral compound +2+2 6(0) 2(-1)

57. Nomenclature of Coordination Compounds: IUPAC Rules The cation is named before the anionThe cation is named before the anion When naming a complex:When naming a complex: –Ligands are named first alphabetical orderalphabetical order –Metal atom/ion is named last oxidation state given in Roman numerals follows in parenthesesoxidation state given in Roman numerals follows in parentheses –Use no spaces in complex name

58. Naming Coordination Compounds

59. Names of Some Common Metallate Anions

60. Names of Some Common Ligands

61. [Co(NН 3 ) 6 ]Cl 3, hexaamminecobalt (III) chloride.[Co(NН 3 ) 6 ]Cl 3, hexaamminecobalt (III) chloride. K 2 [PtCl 6 ], potassium hexachloroplatinate (IV).K 2 [PtCl 6 ], potassium hexachloroplatinate (IV). [Co(NO 2 )(NH 3 ) 3 ], triamminetrinitrocobalt (III)[Co(NO 2 )(NH 3 ) 3 ], triamminetrinitrocobalt (III) [PtCl 4 (NH 3 ) 2 ], diamminetetrachloroplatinum (IV).[PtCl 4 (NH 3 ) 2 ], diamminetetrachloroplatinum (IV).

62. Types of complexes. (i) А complex in which the complex ion carries а net positive charge is called cationic complex: [Co(NН 3 )] 3+ Cl 3 [Ni(NH 3 ) 6 ] 2+ Cl 2 -(i) А complex in which the complex ion carries а net positive charge is called cationic complex: [Co(NН 3 )] 3+ Cl 3 [Ni(NH 3 ) 6 ] 2+ Cl 2 - (ii) А complex in which the complex ion carries а net negative charge is called anionic complex: Na[Ag(CN) 2 ] -, K 4 [Fe (CN) 6 ] 4-(ii) А complex in which the complex ion carries а net negative charge is called anionic complex: Na[Ag(CN) 2 ] -, K 4 [Fe (CN) 6 ] 4- (iii) А complex carrying no net charge is called а neutral complex or simply а complex:(iii) А complex carrying no net charge is called а neutral complex or simply а complex: [Ni(CO) 4 ], [CoCl 3 (NН 3 ) 3 ][Ni(CO) 4 ], [CoCl 3 (NН 3 ) 3 ]

63. 1. With one central atom Ammonia complex [Cu(NH 3 ) 4 ]SO 4 Aqua complex[Al(H 2 O) 6 ]Cl 3 acidic complex K 2 [PtCl 4 ] complex with difference ligands K[Pt(NH 3 )Cl 3 ] cyclic (chelates) Polycentral compoynds Chain [Cr(NH 3 ) 5 – OH – (NH 3 )Cr]Cl 3 chelaes (CO) 5 Mn – Mn(Co) 5 Main types of complex compounds Me O O O O C C NH 2 CH 2 C O N N H2CH2C HOOC COOH CH 2 Me H2CH2C CH 2 C O O O

65. Isomerism IsomersIsomers –compounds that have the same composition but a different arrangement of atoms Major TypesMajor Types –structural isomers –stereoisomers

67. Geometric Isomers

68. Polarimetr

70. Thank you for attention