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Solubility Expressions: كتاب من الحكومة Most pharmacopoeia list the solubility of drugs in terms of number of parts of solvent required to dissolve one part of the drug. لهواء البرشالة. In USP and National Formulary: Solubility is expressed as the number of ml of solvent in which 1 g of solute...

Solubility Expressions: كتاب من الحكومة Most pharmacopoeia list the solubility of drugs in terms of number of parts of solvent required to dissolve one part of the drug. لهواء البرشالة. In USP and National Formulary: Solubility is expressed as the number of ml of solvent in which 1 g of solute will dissolve. E.g. the solubility of boric acid in USP is given as follows: 1 g of boric acid dissolves in 18 ml of water, in 18 ml of alcohol and in 4 ml of glycerin. ‏Intermolecular forces (dispersion forces, dipole-dipole interactions and hydrogen bonds) are much weaker than intramolecular forces (covalent bonds, ionic bonds or metallic bonds) Dispersion forces are the weakest intermolecular force Hydrogen bonds are the strongest intermolecular force rec Dispersion forces dipole-dipole interactions \< hydrogen bonds The London force is sufficient to bring about the condensation of non-polar gas molecules so as to form liquids and solids when molecules are brought quite close to one another. Ion-dipole and ion-induced dipole forces; Occur between polar or non-polar molecules and ions. Ion-induced dipole forces are presumably involved in the formation of the iodide complex. I2 + K+I- K+13- This reaction accounts for the solubility of iodine in a solution of potassium iodide. poly iodide complex Solubility Solubility Solubility of a substance in a particular solvent is \"the concentration of the substance in a saturated solution at certain temperature Saturated solution: من ٤٣ A solution that contains a maximum amount of solute that a solvent can dissolve at certain temperature Unsaturated or sub-saturated: Is the solution that contains dissolved solute in a concentration below that necessary for complete saturation at a definite temperature. Binding forces between molecules There are two main types of forces (intramolecular forces and intermolecular forces): Intramolecular forces قوب Are the forces that keep the atoms in a compound stuck to each other. They are just chemical bonds. Cowlant Bond For example, the force that holds the hydrogen atoms to the oxygen in water molecules are intramolecular forces (covalent bonds). Inter Intermolecular forces: Are the forces that hold two molecules to one another For example, the forces that attract one water molecule to another nearby water molecule are intermolecular forces. These aren\'t chemical bonds instead, they\'re all based on magnetic attractions between different molecules. This attraction is caused by polarity. Physical Band Solvent-solute interaction When the adhesive forces (attraction between the solute- solvent molecules) are more than the cohesive forces (attraction between the solute-solute or solvent-solvent molecules, the solubility of solute in a solvent is generally enhanced. In general (like dissolves like) i.e., polar solvents dissolve polar solutes and non-polar solvents dissolve non-polar solutes. Polar solvent has high dipole moment, and high dielectric constant i.e. high ability to separate oppositely charged bodies. Crystalline solids have low solubility due to The stable crystalline structure Low intermolecular forces between solvent and solute Solutes The solutes (whether gases, liquids or solids) are divided into two main classes; non electrolytes and electrolytes. Non electrolytes are substances whichاون do not yield ions when dissolved in water. Example: sucrose, glycerin, naphthalene and urea, Electrolytes are substances which form ions when dissolved in water (may be weak or strong depending on whether the substance is completely or partially ionized in a solution of moderate concentration اماقتار Eg. HCl, Na sulfate are strong )تاین کامل Weak CHCOOCHs sithong electrolytes and Ephedrine & Phenobarbital are weak electrolytes. Dusolved molecules ( Norelectrodete solution malved ions (NaC Electrolyte solut Solution Sdute + solvent nistersion Khomogen و الداني A mixture of two or more components that form a single phase, which is homogeneous down to the molecular level. مجالس الكمية التكبير Solvent كل الجزيئات مرسومة بنفس المسنين The component that determines the phase of the solution and usually constitutes the largest proportion of the system. So Solute نجم الأكبر Solutes are dispersed as molecules or ions throughout the solvent; i.e. dissolved in the solvent. The solute may be solid, liquid or gas Kinetic theory of matter Gaseous State: The thermal motions of molecules of a substance can overcome the attractive forces that exist between the molecules. Molecules undergo a completely ro غيرات الموجود بن العربيات. عمولی تماما random movement within the confines of the container الجيل العجينة Liquid State: فيه Van der Waals forces of attraction, lead to some degree of coherence between the molecules of liquids. Consequently, liquids occupy a definite volume. Solid State: The intermolecular forces are so strong that a high of order, hardly influenced by thermal motions values are described in the following Tare Parts of Sp Very soluble Less than 1 part 1 to 10 parts Freely subtle 10 to 30-ports Soluble 30 te 100 ports Sparingly sakhle 100 to 1000 parts Slightly soluble Very slightly sahile 1000 to 10,000 perts Practically insalub arinasluble More than 10,000 ports Solubility is abs espresind quantitatively in mat 1 Percentage (%) (w/w) which is the number of grams of solute disselved in 100 grom of solvent ml/ml (w/v) which is the number of mi of sulute dissolved in 100 ml of solvent 9/ml (w/v) which is the runiber of grams of salute dissolved in 100 ml of solvent W glam VmL 2\. Malority (M) عدد المولات الدائية في لتر etdin 1 iter of subvent The number of The set of molority Humber of moles of ster weight) 3. Maliality (m) 1000 glam عدد المولات الذائبة في The runder of meteosedon 1000 gram of solvent The cut of multity is mulg 4\. Normality (N) The aquistent weight of the eluts, expresa in grane int Her of solutio 5\. Mele fraction () Satin of the moles of one constitute of Solution to the total moles of the solution ( solvent) Mate fraction of as Where and numbers of moles of aste and solvent, respectively Determination of solubility An excest attended to the solent and stored for wveral hours at sarampersturent equilibrium is abtoned, proportio Separate the un-lefthe salution by filtration or any other mean of orporation Analytic af the prepared seturst عجيب أحدنا عناية من عليه وتحسب التركيز Solubility is abs espresind quantitatively in mat 1 Percentage (%) (w/w) which is the number of grams of solute disselved in 100 grom of solvent ml/ml (w/v) which is the number of mi of sulute dissolved in 100 ml of solvent 9/ml (w/v) which is the runiber of grams of salute dissolved in 100 ml of solvent W glam VmL 2\. Malority (M) عدد المولات الدائية في لتر س The number of etdin 1 iter of subvent The set of molority Humber of moles of ster weight) 3. Maliality (m) 1000 glam عدد المولات الذائبة في The runder of meteosedon 1000 gram of solvent The cut of multity is mulg 4\. Normality (N) The aquistent weight of the eluts, expresa in grane int Her of solutio 5\. Mele fraction () Satin of the moles of one constitute of Solution to the total moles of the solution ( solvent) Mate fraction of as Where and numbers of moles of aste and solvent, respectively Determination of solubility An excest attended to the solent and stored for wveral hours at sarampersturent equilibrium is abtoned, proportio Separate the un-lefthe salution by filtration or any other mean of orporation Analytic af the prepared seturst عجيب أحدنا عناية من عليه وتحسب التركيزThe solubility of a gas in a liquid is the concentration of The dissolved gos in the lid when it is in squilibrius with some of the pure ges above the solution 1\. The pressure The solubility of gases in liquids depend an العيد 2\. The temperature 3\. The presence of solts 4\. The chemical reaction of the ges with the solvent. اسات 2\. Effect of Temperature: As the temperature wressed the shility of meste to the greater tendency of the gesto xpand Se The pharmacist must be carefd in spening contumers of in worms cinctes Al conting Squid with such as ethyl nitrate, should be anmersed te we cold water for a tone to reduce the operand pressure of the gas before spening the 1\. Effect of Prouare The affart of the prestreonthey of Hary\'s La Where Cs the concesiothe Iter of achvent Pis the portul pressure the dasilved gui is proportionality care st the solityce 3\. Solting Out Solubility of goes ingannally reduced by electrolyte such en supe youth to the more affinity betwee solvent and the slectrolyte or no electrolyte than the solvent and the dashed4. Effect of Chemical Reaction: SO V Henry\'s law applies strictly to gases which are only slightly soluble in solution and which do not react in any way in the solvent. Chemical reaction if any between a gas and a solvent greatly increases the solubility of the gas in the solvent. E.g., hydrogen chloride gas reacts with water by hydrogen bonding, this reaction increases the solubility of hydrogen chloride gas in water. Va