Mixtures, Solubility, and Solutions Chapter 13 Mixtures, Solubility, and Solutions

13.1-Substances and Mixtures A substance is matter with composition that is always the same Two major types of substances Elements Compounds

13.1-Substances and Mixtures Elements are substances that consist of just one type of atom Elements are found on the periodic table Each element has its own characteristic properties. These include boiling/melting point, density, reactivity, flammability, etc. An element may share one or two properties with another element, but it will not share all its properties with another element. There will be specific properties for each element.

13.1-Substances and Mixtures Compounds are substances containing atoms of two or more different elements chemically bonded together Occurs as a result of a chemical reaction Compounds are represented by chemical formulas Ex. NaCl, CO2, H2O

13.1-Substances and Mixtures Properties of compounds Compounds have a SET RATIO Ex. H2O (water) vs H2O2 (hydrogen peroxide) Each compound has its own physical properties and chemical properties. The properties of a compound are different from the properties of the elements that form it. Sodium + Chlorine  Table Salt Explosive soft metal Yellow Piousness Gas

13.1-Substances and Mixtures Are they elements or compounds?

13.1-Substances and Mixtures What is a mixture? A Mixture is two or more substances that are physically blended but are not chemically bonded together No chemical reaction No compound formed Each substance keeps its original identity No fixed ratio—NOT always the same

13.1-Substances and Mixtures Types of Mixtures Heterogeneous Homogeneous

13.1-Substances and Mixtures A heterogeneous mixture is a type of mixture in which the individual substances are unevenly mixed Two different samples of the same mixture can have different amounts of substances Example: salad, pizza, granola bar

13.1-Substances and Mixtures Types of heterogeneous mixtures Suspension A suspension is a mixture in which particles are large enough to be dispersed, but they settle out over time Can be filtered, can scatter light Colloid A colloid is a mixture in which the particles are medium in size and dispersed throughout but are not heavy enough to settle out Cannot be filtered, can scatter light

13.1-Substances and Mixtures A homogeneous Mixture is a type of mixture in which the individual substance are evenly mixed Example: Apple juice, salt water Appears to be a single substance due to small particles Cannot be filtered, cannot scatter light Also known as a solution

13.1-Substances and Mixtures   Solution Colloid Suspension Particle size: S, M, L  small  medium  large Filter?  no  yes Scatter light? Settle out?  No no Yes Two examples  Salt water Kool Aide  Mayo milk  Italian dressing Snow globe

13.1-Substances and Mixtures Compounds Made of elements, compounds or both Made of elements No change in original properties of components Change in original properties of components Separated by physical means Separated by chemical means Formed by using any ratio of components Formed using a set ratio of components

13.2- Properties of Solutions Parts of a solution The solute is the substance that is dissolved The solvent is the substance that exists in the greatest quantity in a solution

13.2- Properties of Solutions Concentration of Solutions The concentration is the amount of a particular solute in a given amount of solvent Units: g/mL Lots of solute  concentrated Little solute dilute

13.2- Properties of Solutions The term soluble means able to dissolve. Insoluble means unable to dissolve. Solutions can be solids, liquids, or gases. Solubility- is the maximum amount of solute that can dissolve in a given amount of solvent at a given temperature and pressure

13.2- Properties of Solutions Solubility Saturated solutions are solutions that contain the maximum amount of solute that the solution can hold at a given temperature and pressure Unsaturated solutions are solutions that can still dissolve more solute at a given temperature and pressure

13.2- Properties of Solutions How does temperature affect solubility? For liquid solvents A higher temperature decreases the solubility of a gas A higher temperature inceases the solubility of a solid or liquid How does pressure affect solubility? A higher pressure increases the solubility of a gas

13.2- Properties of Solutions What is a solubility curve? This is a graph that shows how solubility of a substance can change with temperature Reading the graph X-axis – temperature Y-axis – solubility

To what temperature would water have to be heated if I wanted to dissolve 70 grams of NH3? To what temperature would water have to be heated if I wanted to dissolve 70 grams of NH4Cl? How many grams of KClO3 can be dissolved into 100 g H2O heated to 70°C? How many grams of KClO3 can be dissolved into 100g H2O heated to 45°C?

13.2- Properties of Solutions How fast a solute dissolves All speed up dissolving

Mixture vs. compound vs. element

Elements, Compounds, Mixtures   Elements Compounds Mixtures How many parts make it up?  1  2 or more  2 or more elements or compounds Pure: more than one substance?  pure  Not pure Chemically or physically combined?  N/A  Chemically physically Chemical change to make them?  Yes no Fixed ratio? Yes How separated: chemically/ physically? Chemically