180 likes | 513 Views
Unit 4: Solutions and Solubility. EXCELLENT STUDY GUIDE VIDEO FOR SOLUBILITY: http://www.youtube.com/watch?v=D2NAw-A0V1s. Recall…. Classification of Matter. All matter around us can be classified as pure substances or mixtures Pure substances include elements and compounds
E N D
Unit 4: Solutions and Solubility EXCELLENT STUDY GUIDE VIDEO FOR SOLUBILITY: http://www.youtube.com/watch?v=D2NAw-A0V1s
Classification of Matter • All matter around us can be classified as pure substances or mixtures • Pure substances include elements and compounds • Mixtures can be heterogeneous or homogeneous
Solutions • Solution – homogeneous mixture that is uniform throughout itself • Simple solutions contain only two substances • Most solutions contain many substances
Solutions cont. • A solvent is a substance that has other substances dissolved in, usually in the largest amount • A solute is the substance that is being dissolved
Separation of Solutions • When a solute dissolves in a solvent, no chemical reaction occurs • Solutions can be a gas, liquid, or solid
Solutions cont. • An aqueous solution is a solution in which water is the solvent • Miscible substances readily combine with each other • Immiscible substances do not dissolve with each other
Solutions cont. • The solubility of a solute is the amount of solute that dissolves given an amount of solvent at a certain temperature
Solutions cont. • Example: What is the solubility of sugar at 80oC? • 350g/100mL
Solubility • Unsaturated solution– a solution that still has the ability to dissolve more solute • Saturated solution– a solution that is at its saturation point and is unable to dissolve more solute • Super saturated solution– a solution that has dissolved beyond its saturation point due to heating of the solution • http://www.youtube.com/watch?v=D1PDE5OawuI
Example for NaNO3 • What kind of solution will I have if I heat 140 kg of NaNO3 to 60 degrees?
Factors that Affect Solubility To dissolve something at the molecular level: • Forces between the particles in the solid must be broken (broken between ions or molecules), which requires energy • Some of the intermolecular forces in the liquid must be broken, which requires energy
Factors that Affect Solubility • Molecule Size – the smaller it is, the easier it dissolves • Temperature – increases dissolving ability of solids, most liquids, but decreases solubility of gases • Pressure – does not affect dissolving ability of solids and liquids, but increases solubility of gases