1. Aqueous solutions and Colloids

2. Solutions and Colloids are essential to life, the solutions in living systems are aqueous solutions that is they are made with water. Solutions:- homogenous mixture of two or more different substance the substances that make up the solution are called it's component, one of these component is more than the other's & called (solvent), the other component called solute (e.g.) sugar in water.

3. The three states of matter can combine in nine different ways to form collations containing two components these are listed in table (1). Solvent Solute Solvent Solute ــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــ ــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــ Liquidliquid Liquidliquid Liquidsolid Liquidgas Solidsolid Solidliquid Solidgas Gasgas Gasliquid Gassolid Solutions that contain liquids as solutes are the types of solutions most familiar to us. Numerous examples of solutions containing solids in liquids, liquid is liquid gases in liquid are available from everyday experiences.

4. SolubilitySolubility The amount of solute dissolved in a given quantity of to form saturated solution at central temperature. The solubility of a solute in certain solvent, depend on: 1. Kind of solute 2. Kind of solvent 3. Temperature Vapor pressure Solubility in crease with increasing temperature & by increasing the vapor pressure there are two type of solvent. 1. polar solvent like H 2 O & Alcohol 2. non polar solvent like benzene & ether The polar solvent like NaCl. Gasoline a mixture of no polar organic compounds is good solvent for other no polar organic compounds such as greases and oils; its follows from the general rule that polar and non polar substances will not form solutions e.g. gasoline and water.

5. SolubilitySolubility Some liquids are infinitely soluble in another liquid like ethyl alcohol and water such pair of liquids is said to be(1) completely miscible. Other liquid are slightly soluble in each other, such liquids are said to be (2) partially miscible. liquids that are insoluble in each other are said to be (3) immiscible like gasoline & water.

6. The temperature of solvent affect the solubility of solute is general solutes are more soluble in hot than cold solvent the sol abilities of several solids in crease greatly with in increasing temp, other increase slightly, and some actually decrease. Gases are compound whose solubility's decrease with in creasing temp because the bubbles that from when water is heated are air escaping from solution because dissolved air is less in water at higher temp. In general the solubility of any gas increases as the partial pressure of the gas above the solution is increased.

7. Electrolytes and non Electrolytes

8. A aqueous solution either conduct electricity or not one that conduct electricity is called an electrolytic solution like NaCl, CaCl 2, the other that doesn't conduct electricity called non electrolytic solution like sugar. A solute that forms an aqueous electrolytic solution is called electrolyte. A solute that form non electrolytic solution called (non electrolytes).

9. Arrhenius Theory of Electrolyte Arrhenius proposed that molecule dissolved in water to form particles that mix completely with solvent molecule, Electrolytes and non electrolytes form different particles when they dissolved in water, all electrolytes are compounds that contain ionic bond when dissolved in water, the ions are released & distribute themselves uniformly in the water in addition to salts many compounds with polar covalent bond also form ion when dissolved in water. When non electrolyses dissolved in water neutral molecule released rather than ions, such association of water molecule with an ion is called (hydration) & we say the ion is hydrated, aqueous solution of electrolytes are relay solutions of hydrated ion. When non electrolyses dissolved in water neutral molecule released rather than ions, such association of water molecule with an ion is called (hydration) & we say the ion is hydrated, aqueous solution of electrolytes are relay solutions of hydrated ion.

10. The total number of ions formed per 1mole of the electrolytes. e.g: no of mole of CaCl 2 = 1 mole of Ca +2 1mole Cl - + 1 mole Cl - = 3 mole = 3 mole So no of ions = no of mole X Avogadro NO = 3 mole X 6.02 X 10 23 = 3 mole X 6.02 X 10 23

11. Osmosis & Osmotic Pressure Osmoses:- is the movement of water through an osmotic membrain from an aqueous solution that is less concentrated to one that more concentrated soln. soln. Low conc. ـــــــــــــــــــــــــــــــ high conc. Low conc. ـــــــــــــــــــــــــــــــ high conc.

12. Osmotic membrane Semi permeable membrane:- material that allow only certain molecules to pass through it, it contain small holes, there fore the molecule larger than holes will not pass through this selectivity responsible for osmosis.

13. Osmotic Pressure The pressure needed to prevent osmosis called osmotic pressure of solution. Notice that a high solute concentration means high osmotic pressure. Water move from dilute to more concentrated solution to make the concentration of the two solutions equal. The osmotic pressure of 1mole NaCl exactly twice that of 1 mole Glucose because Nacl is electrolyte& contain 1 mole of Na + and mole of Cl - but glucose is not electrolyte. Glucose because Nacl is electrolyte& contain 1 mole of Na + and mole of Cl - but glucose is not electrolyte. 1 mole of Na+ + 1 mole of Cl - = 2 mole glucose = 1 mole glucose = 1 mole : Nacl in osmotic pressure > glucose : Nacl in osmotic pressure > glucose

14. The greater no of particles (ions) or molecules in a solution the greater it's osmotic pressure. Any properties of a solution that depend on the number of dissolved particles in the solvent is called colligative property. The relative osmotic pressure of two solutions are important in living system, so we described as two solutions that have same osmotic pressure are said to be (isotonic solution), e.g 1 mole glucose equally = 1 mole urea because the two solution is (no electrolyte) and they have the same osmotic pressure, if one solution have a higher osmotic pressure than the other it said to be hypertonic (e.g) 1M Nacl & 1 M glucose 1M Nacl & 1 M glucose 2M LiBr & 1 M Nacl 2M LiBr & 1 M Nacl

15. The 1 molar of Nacl has higher osmotic pressure than 1M glucose because 1 mole Na + 1 mole Cl = 2 mole 1 mole Na + 1 mole Cl = 2 mole : Nacl more osmotic pressure > glucose : Nacl more osmotic pressure > glucose 2 M LiBr has higher osmotic pressure than 1 M Nacl because 2 X 2 = 4> 2 of Nacl 2 X 2 = 4> 2 of Nacl If one of solutions has the lower osmotic pressure is said to be (hypotonic) solution compare to other e.g. 0.6 M glucose & 1M glucose e.g. 0.6 M glucose & 1M glucose 1 M LiBr & 2M NaF. 1 M LiBr & 2M NaF.

16. Red Blood Cell The plasma membrane of R. B. C behave as osmotic membrain osmosis occur when R.B.C is placed in placed in H 2 O, the solutions inside the cell is (hypertonic) so H 2 O enter the cell & make (rapture) the rapture of R.B.C is called hemolysis, but if R.B.C put in normal saline (NaCl) water leave the cell and make shrink this called cremation