Chem 116 Lecture Note Outlines Set 01: Solutions intro Spring 2015 (Ratcliff) Everything in life comes to you as a teacher. Pay attention. Learn quickly. Page 1 of 5 Chemistry ≡ is the study of matter, its transformations and the energy associated with these changes Matter ≡ anything that has both mass and volume ⇒ the “stuff” of the universe Why study chemistry? ♦ learn fundamental physical models of “stuff” ♦ gain technical perspective on current events ♦ develop problem solving skills ♦ appreciate life's little mysteries Chapter 13: The Properties of Mixtures Solutions and Colloids Matter Pure substances [Chem 115] ♦ elements ♦ compounds Mixtures [Chem 116] ♦ combination of two or more substances ♦ no chemical reaction occurs upon mixing ♦ physical properties of the mixture, may differ from those of its components ♦ can be homogeneous or heterogeneous Homogeneous Mixtures ♦ Only one phase is present ♦ uniform in appearance and composition ♦ Types: suspensions, colloids, and solutions Heterogeneous Mixtures ♦ Visibly different partsChem 116 Lecture Note Outlines Set 01: Solutions intro Spring 2015 (Ratcliff) Everything in life comes to you as a teacher. Pay attention. Learn quickly. Page 2 of 5 Suspensions Colloids Solutions Particle size Larger than 1µm (1000 nm) intermediate in size, 1 – 1000 nm Very small; that of atoms or molecules (less than 1 nm) Settle out? Yes No No Separate with paper filter? Yes No No Separate with membrane? Yes Yes No Appearance Cloudy, milky, or opaque cloudy and milky, or opaque Clear, not cloudy Affect colligative properties? No No Yes Examples Blood, paint, some medicines (shake before use) milk, smoke, some cloudy solutions in lab Sugar in water, atmospheric air, steel Tyndall effect ≡ scattering of light as a light beam passes through a colloid Example of types of Solutions Component 1 Component 2 examples Gas Gas Gas Liquid Liquid Liquid Solid Liquid Liquid Solid Solid SolidChem 116 Lecture Note Outlines Set 01: Solutions intro Spring 2015 (Ratcliff) Everything in life comes to you as a teacher. Pay attention. Learn quickly. Page 3 of 5 Review: Types of intermolecular forces in solutions Ion− dipole (40-600 kcal/mole) Hydrogen bonding (10-40 kcal/mole) Dipole−dipole (5-25 kcal/mole) Ion− induced dipole (3-15 kcal/mole) Dipole− Induced dipole (2-10 kcal/mole) Dispersion (0.05-40 kcal/mole) [Note: Review intermolecular forces (p. 430 – 437) if you are ‘fuzzy’ on IMF’s ]Chem 116 Lecture Note Outlines Set 01: Solutions intro Spring 2015 (Ratcliff) Everything in life comes to you as a teacher. Pay attention. Learn quickly. Page 4 of 5 General Rule of Thumb: Solutes will dissolve in solvents with similar IMF’s ♦ ‘Polar solutes will readily dissolve in Polar solvents’ ♦ ‘Nonpolar solutes will readily dissolve in Nonpolar solvents’ ♦ “Like dissolves Like” Concept Check Predict the solubility of iodine and CuSO4 in both water and hexane (C6H12). CuSO4 in water CuSO4 in hexane I2 in water I2 in hexane a. soluble soluble insoluble insoluble b. soluble insoluble insoluble soluble c. insoluble insoluble soluble soluble d. insoluble soluble soluble insoluble But why does “Like dissolves Like”? When I2 dissolves in water ♦ I2−to−I2 forces and H2O−to−H2O interactions are replaced by I2−to−H2O interactions. ♦ This can only occur if the solute-solvent attractions are similar to those they replaceChem 116 Lecture Note Outlines Set 01: Solutions intro Spring 2015 (Ratcliff) Everything in life comes to you as a teacher. Pay attention. Learn quickly. Page 5 of