Presentation on theme: "SOLUTION AND COLLOID SPECIFIC LEARNING OBJECTIVE"— Presentation transcript:
1 SOLUTION AND COLLOID SPECIFIC LEARNING OBJECTIVE At the end of the session the student should be able to explain:Definitions of Solution and ColloidsSystem of Solutions and ColloidsType of Solutions and Colloids
2 INTRODUCTION Types of solution Concentration SOLUTION No.1INTRODUCTIONTypes of solutionNo.2ConcentrationNo.3SOLUTIONSolution propertiesNo.4DialysisNo.5
5 CLASSIFICATION OF MATTER MixturePure substanceHomogeneous mixtureHeterogeneous mixtureElementCompound
6 HOMOGENEOUS MIXTURE Homogenous mixtures called solutions And Their distant relatives, colloidal suspensions
7 SolutionsSolutions are homogeneous mixtures of two or more substances in which the components are present as atoms, molecules, or ionsThese uniformly distributed particles are too small to reflect light, and as a result solutions are transparent (clear) – light passes through them
8 SUBSTANCES OF SOLUTIONS SoluteSolventThe most abundant substance in a solution is called solventThe substance is dissolved in a solvent is called solute
9 SOLUTE Solute Electrolyte Nonelectrolyte A solute that when dissolved in water forms a solution that conducts electricity.NonelectrolyteA solute that when dissolved in water forms a solution that does not conduct electricity.
10 HEATS OF SOLUTION Heat is usually absorbed or released when a solute dissolves in a solvent.The process is endothermic, if heat is absorbed, and solution becomes cooler.The process is exothermic, if heat is released, and solution temperature increases.Endothermic : Solute + Solvent + HeatSolution (NH4NO3 in water)Exothermic : Solute + SolventSolution + Heat (NaOH in water)
11 INTRODUCTION Types of solution Concentration SOLUTION No.1INTRODUCTIONTypes of solutionNo.2ConcentrationNo.3SOLUTIONSolution propertiesNo.4DialysisNo.5
12 SOLUTION Types of solution Chemical term Medical term No. 2Chemical termMedical termUnsaturatedSaturatedSuper saturatedHypotonicIsotonicHypertonic
13 Classification of Solubility Chemical termSOLUBILITYClassification of SolubilityThree classify of solubility of a compound1. Soluble2. slightly soluble3. insoluble
14 Soluble substances dissolve completely in the solvent and form solution Insoluble substances do not dissolve in the solventThe term immiscible is used to describe a liquid solute that does not dissolve in a liquid solvent
15 SOLUBILITY 1. Soluble 2. slightly soluble 3. insoluble Depend on the Polarity1. Soluble2. slightly soluble3. insolubleThree type of polarity of a compound :1. Polar2. Semipolar3. Nonpolar
16 UNSATURATED, SATURATED AND SUPERSATURATED SOLUTIONS SOLUBILITYSaturated solution, is a solution that contains the maximum amount of a solute in a given solvent, at a specific temperature.Unsaturated solution, is a solution that contains less solute that it has the capacity to dissolve.Supersaturated solution, contains more solute than is present in a saturated solution
17 SUPERSATURATED SOLUTIONS Supersaturated solutions are usually prepared by forming a nearly saturated solution at a high temperature and then slowly cooling the solution to a lower temperature at which the solubility is lower. Such solutions are not stable. The addition of small amount of solid solute (or even a dust particle) will usually cause the excess solute to crystallize out of solution until the solution becomes saturated.
18 CRYSTALLIZATION CONVERTS A SUPERSATURATED SOLUTION TO A SATURATED SOLUTION A supersaturated Seed crystal is added After excess solute issolution and induces rapid crystallized, thecrystallization remaining solution issaturated
19 SOLUTION Types of solution Chemical term Medical term No. 2Chemical termMedical termUnsaturatedSaturatedSuper saturatedHypotonicIsotonicHypertonic
20 Hypotonic, Isotonic and Hypertonic solutions Medical termHypotonic, Isotonic and Hypertonic solutionsHypotonic solutions : the solution with the lower concentration of soluteIf the concentration of water in the medium surrounding a cell is greater than that of the cytosol. Water enters the cell by osmosisIsotonic solutions : the solution being compared have equal concentration of solutes.When red blood cells are placed in a 0.9% salt solution, they neither gain nor lose water by osmosisHypertonic solutions : The solution with the higher concentration of solutes.If red cells are placed in sea water (about 3% salt), they lose water by osmosis and the cells shrivel up.
21 Red blood cells in the Hypotonic, Isotonic and Hypertonic solutions with hypotonicsolutionRed blood cellswith isotonicsolutionRed blood cellswith hypertonicsolution
22 INTRODUCTION Types of solution Concentration SOLUTION No.1INTRODUCTIONTypes of solutionNo.2ConcentrationNo.3SOLUTIONSolution propertiesNo.4DialysisNo.5
23 continued to next slide SOLUTIONConcentrationNo. 3Molarity (M)Percent (%)Molarity (M) :a solution concentration that is expressed in term of the number of moles of solute contained in a liter of solution.Percent : a solution concentration that expresses the amount of solute in 100 parts of solution.continued to next slide
24 continued to next slide SOLUTIONConcentrationNo. 3Molality (m)Normality (N)Molality (m) :a solution concentration that is expressed in term of the number of moles of solute contained in a kilogram of solvent.Normality (N) : a solution concentration that is expresses in term of the number of gram equivalent of solute contained in a liter of solvent.continued to next slide
25 Continuation :Weight/weight percent : a concentration that expresses the mass of solute contained in 100 mass units of solution.Weight/volume percent : a concentration that expresses the grams of solute contained in 100 ml of solution.Volume/volume percent : a concentration that expresses the volume of liquid solute contained in 100 volume of solution.
26 DILUTION The volumetric scales of concentration are those, like molar concentration and normality,in which the concentration is expressed on avolumetric scale, the amount of solute perfixed volume of solution, when theconcentration is expressed on a volumetricscale, the amount of solute contained in agiven volume of solution is equal to theproduct of the volume and the concentration:Amount of solute = volume x concentrationcontinued
27 If a solution is diluted, the volume is increased and the concentration is decreased, but thetotal amount of solute is constant. Hence, twosolutions of different concentrations butcontaining the same amounts of solute will berelated to each other as follows:Volume1 x concentration1 = Volume2 x concentration2continued
28 If any three terms in the above equation are continuedIf any three terms in the above equation areknown, the fourth can be calculated. Thequantities on both sides of the equation mustbe expressed in the same units
29 INTRODUCTION Types of solution Concentration SOLUTION No.1INTRODUCTIONTypes of solutionNo.2ConcentrationNo.3SOLUTIONSolution propertiesNo.4DialysisNo.5
30 SOLUTION Colligative properties (continued to next slide) SOLUTION PROPERTIESNo. 4Electrical conductivity andcolligative propertiesColligative properties (continued to next slide)
31 COLLIGATIVE PROPERTIES The properties that depend only on the concentration of solute particles present and not on the actual identity of the solute.Three closely related colligative properties are1. Vapor pressure2. Boiling point3. Freezing point4. Osmotic pressure
32 The equation for calculated the boiling point or freezing point difference between pure solvent and solutionΔ tb = nKbmΔ tf = nKfmΔ t is the boiling point or freezing point difference between pure solvent and solution.Kb and Kf are constants characteristic of the solvent used in the solution.
33 for example : Calculate the boiling and freezing points of the following solutions 171.0 g of sugar (C12H22O11) is dissolved in 1.00 kg of water, Kb = C/m and Kf = C/mAnswer :a. To fine the boiling point, calculate solutionmolality :171.0 g (C12H22O11) mol C12H22O =342.0 g C12H22O11= mol C12H22O11m = moles of solute/1 kg of solvent = 0.50 mol/1.0 kg= 0.50 mol/kg continued to next slidex
34 Continuation:b. Determine n : because sugar does notdissociate upon dissolving, n = 1.c. Δ tb = nKbm = (1)(0.52 0C/m)(0.50m)= 0,26 0Cd. Δ tf = nKfm = (1)(1.86 0C/m)(0.50m)= 0,93 0C
35 OSMOTIC PRESSUREIs the hydrostatic pressure required to prevent the net flow of solvent through a semipermeable membrane into a solution.Osmotic pressure () = nMRT (van’t Hoff equation)T = temperature in KelvinsR = the ideal gas constant(0.82 L-atmosphere/degree.mole)M = the solution molarity
36 OSMOSISThe process in which solvent flows through a semipermeable membrane into a solution.
37 INTRODUCTION Types of solution Concentration SOLUTION No.1INTRODUCTIONTypes of solutionNo.2ConcentrationNo.3SOLUTIONSolution propertiesNo.4DialysisNo.5
38 SOLUTIONDialysisNo. 5Earlier we discussed semipermeable membranes that selectively allow solvent to pass but retain dissolved solutes during osmosis.Dialysis, another membrane process, is also important in living organisms.
39 ContinuationDialyzing membranes :A semipermeable membranes with pores large enough to allow solvent molecules, other small molecules, and hydrat ions to pass through (are semipermeable membranes with larger pores than osmotic membranes).
40 ContinuationDialysis : A process in which solvent molecules, other small molecules, and hydrat ions pass from a solution through a membrane (is the passage of ions and small molecules through such membranes).
41 DIALYSIS. This is one method of dialysis used to purify proteins
43 Application of Dialysis Dialysate + waste productDialysis tubingFresh dialysateScheme of dialysis process
44 A similar technique is used to clean the blood of people suffering kidney mal function The blood is pumped through tubing made of a dialyzing membrane.The tubing passes through a bath in which impurities collect after passing out of the blood.Blood proteins and other important large molecules remain in the blood.
45 Scheme of hemodialysis process blooddialysatdialysatbloodScheme of hemodialysis process
46 ContinuationDialysis is most commonly used to remove salts and other small molecules from solutions of macromolecules. During the separation and purification of biomolecules, small molecules are added to selectively precipitate or dissolve the desire molecule.
47 ContinuationDialysis is also useful for removing small ions and molecules that are weakly bound to biomolecules. Protein cofactors such as NAD, FAD, and metal ions can be dissociated by dialysis. The removal of metal ions is facilitated by the addition of a chelating agent (EDTA) to the dialysate.Minerals are bound by EDTA, these are: Ca, Fe, etc.
50 INTRODUCTION Types of colloid COLLOID Colloid properties No.1INTRODUCTIONNo.2Types of colloidCOLLOIDNo.3Colloid properties
51 INTRODUCTION : ° Definition ° Diameter of colloid particle No. 1INTRODUCTION : ° Definition ° Diameter of colloid particle
52 Definitioncolloids (or colloidal suspensions) are homogeneous mixture of two or more components in which there is more of one component than of the others.In solutions the terms solvent and solute are used for the components, but in colloids the terms dispersing medium (for solvent) and dispersed phase (for solute) are used.
53 DIAMETERS OF THE DISPERSED PHASE The dispersed phase of colloids is made up of much larger particles (very large molecules or small pieces of matter) with diameters:10ˉ7 to 10 ˉ5 cm (10 – 1000 A˚)
54 INTRODUCTION Types of colloid COLLOID Colloid properties No.1INTRODUCTIONTypes of colloidNo.2COLLOIDNo.3Colloid properties
56 TYPES OF COLLOID Type Name Examples Aerosol Foam Emulsion Sol Solid foamFog, aerosol sprays, some air pollutantsSmoke, some air pollutantsWhipped cream, shaving creamMilk, mayonnaisePaint, ink, gelatin dessertMarshmallow, pumice stone, foam rubberButter, cheesePearls, opals, colored glass, some metal alloysDispersing mediumDispersed phaseGasLiquidSolid
57 LYOPHOBIC AND LYOPHILIC SYSTEM Colloidal solutions with a liquid asDispersion medium can be dividedroughly into two Categories :Lyophilic SolsLyophobic Sols
58 DIFFERENCES BETWEEN THE TWO TYPES SURFACE TENSION SIMILAR TO THAT OF DISPERSION MEDIUM.VISCOSITY SIMILAR TO THAT OF MEDIUM.SMALL QUANTITIES OF ELECTROLYTES CAUSE PRECIPITATION.THE PARTICLES ARE EASILY DETECTED IN THE ULTRAMICROSCOPE.THE PARTICLES MIGRATEIN ONE DIRECTION IN AN ELECTRIC FIELD.SURFACE TENSION OFTEN LOWER THAN THAT OF DISPERSION MEDIUM.VISCOSITY MUCH HIGHER THAN THAT OF MEDIUM.SMALL QUANTITIES OF ELECTROLYTES HAVE LITTLE EFFECT, BUT LARGE AMOUNTS MAY CAUSE SALTING OUT.THE PARTICLES CANNOT BE READILY DETECTED IN THE ULTRAMICROSCOPE.THE PARTICLES MAY MIGRATE IN EITHER DIRECTION OR NOT AT ALL IN ELECTRICAL FIELD.
59 INTRODUCTION Types of colloid COLLOID Colloid properties No.1INTRODUCTIONNo.2Types of colloidCOLLOIDNo.3Colloid properties
60 EMULSIFYING AGENTS OR STABILIZING AGENTS COLLOIDNo.3Colloid propertiesTYNDALL EFFECTBROWNIAN MOVEMENTCOLLOID FORMATIONCOLLOID DESTRUCTIONEMULSIFYING AGENTS OR STABILIZING AGENTS
61 TYNDALL EFFECTWhen a beam of light passes through them, they will be scattered the light, and the path of the light becomes visible.And hence it is generally called the Tyndall effect.
62 source colloid CuSO4 Fe(OH)3 The light beam passes from left to right through a purple gold sol (a colloid), a blue copper sulfate solution, and colloidal iron (III) hydroxide. The light path can be seen in both colloids, but not in the copper sulfate solution.
63 BROWNIAN MOVEMENTAs is to be expected, because of their small size, colloidal particles are seen in the ultramicroscope to display vigorous Brownian movement.
64 COLLOID FORMATION AND DESTRUCTION Much of the interest in colloids is related to their formation or destruction.Colloid particles tend to attract and absorb ions that are present in the dispersing medium.The charge (+ or -) of the adsorbed ions depends on the nature of the colloid, but all colloid particles within a particular system will attract only one charge or the other.This repulsion help prevent the particles from coalescing into aggregates large enough to settle out.
65 EMULSIFYING AGENTS OR STABILIZING AGENTS Emulsifying agents is substances that stabilize the colloids (prevented from coalescing)For examples :1. Egg : the compound in the eggyolk acting as the emulsifyingagents2. Soaps and detergents3. Etc (CMC = carboxyl methyl cellulose )
66 Summary Reference:Mushtaq Ahmad, Essentials of Medical Biochemistry 6th Edition, Vol.1-2, Merit Publisher, Multan, 1999