1. Seperating Mixtures
1.1. Seperation Techniques
1.1.1. Seperating Soluble Substances
1.1.1.1. Distillation:
1.1.1.1.1. Purpose: Separates liquids with different boiling points or a liquid from a dissolved solid.
1.1.1.1.2. How it works: The mixture is heated to boil off one liquid, which is then condensed and collected.
1.1.1.1.3. Example: Separating alcohol from water.
1.1.1.2. Evaporation:
1.1.1.2.1. Purpose: Separates a dissolved solid from a liquid.
1.1.1.2.2. How it works: The liquid is heated to evaporate, leaving the solid behind.
1.1.1.2.3. Example: Salt from saltwater.
1.1.1.3. Chromatography:
1.1.1.3.1. Purpose: Separates components of a mixture based on their movement through a medium.
1.1.1.3.2. How it works: The components move at different rates, creating a separation.
1.1.1.3.3. Example: Separating pigments in ink.
1.1.2. Seperating Insoluble Substances
1.1.2.1. Centrifugation:
1.1.2.1.1. Purpose: Separates components with different densities.
1.1.2.1.2. How it works: The mixture is spun at high speeds, forcing heavier components to the bottom.
1.1.2.1.3. Example: Separating cream from milk.
1.1.2.2. Magnetic Separation:
1.1.2.2.1. Purpose: Separates magnetic materials from non-magnetic materials.
1.1.2.2.2. How it works: A magnet is used to attract magnetic components.
1.1.2.2.3. Example: Iron filings from sand.
1.1.2.3. Filtration:
1.1.2.3.1. Example: Sand and water.
1.1.2.3.2. Purpose: Separates insoluble solids from liquids.
1.1.2.3.3. How it works: A filter traps solid particles while allowing the liquid to pass through.
1.1.2.4. Decanting:
1.1.2.4.1. Purpose: Separates a liquid from an insoluble solid that has settled at the bottom.
1.1.2.4.2. How it works: The liquid is carefully poured off, leaving the solid behind.
1.1.2.4.3. Example: Water from settled mud.
1.1.2.5. Sieving
1.1.2.5.1. Purpose: Separates larger particles from smaller ones in a mixture.
1.1.2.5.2. How it works: The mixture is passed through a sieve with holes that allow smaller particles to pass through while larger ones are left behind.
1.1.2.5.3. Example: Separating pebbles from sand.
1.2. Mixtures can be separated by physical methods
1.3. Choosing the Best Tecnique
1.3.1. To determine the best technique, answer these questions:
1.3.2. Is the solid dissolved or undissolved? (Filtration for undissolved, evaporation for dissolved)
1.3.3. Do the components have different boiling points? (Distillation)
1.3.4. Is one part magnetic? (Magnetic separation)
1.3.5. Are the particles small and remain suspended? (Centrifugation)
2. Mixtures
2.1. Each substance in a mixture keeps its own properties.
2.2. Definition: A material made of two or more substances physically combined, not chemically bonded.
2.3. Characteristics of Mixtures
2.3.1. Concentration and Dilution
2.3.1.1. Making a solution more dilute: Add more solvent to the solution (e.g., adding more water to dilute orange juice).
2.3.1.2. Making a solution more concentrated: Add more solute to the solution (e.g., adding more sugar to water).
2.3.2. Saturated and Unsaturated Solutions
2.3.2.1. Saturated Solution: A solution that has dissolved as much solute as it can at a given temperature. Any additional solute will not dissolve and may settle at the bottom.
2.3.2.2. Unsaturated Solution: A solution that can dissolve more solute at a given temperature. For example, if you add a teaspoon of salt to a cup of water and it all dissolves, the solution is unsaturated.
2.4. Key Characteristics:
2.4.1. Can be physically separated into their components.
2.4.2. Each component keeps its own properties.
3. Pure Substances
3.1. Definition: A material made of only one type of particle or component, with a fixed composition.
3.2. Key Characteristics:
3.2.1. Cannot be physically separated into other substances.
3.2.2. Has consistent properties throughout.
3.3. Types:
3.3.1. Elements: Made of only one type of atom (e.g., oxygen, gold).
3.3.2. Compounds: Made of two or more elements chemically bonded (e.g., water (H₂O), salt (NaCl)).
3.4. Examples:
3.4.1. Diamond (pure carbon).
3.4.2. Distilled water (pure H₂O).
4. Physical & Chemical Properties
4.1. Physical Properties
4.1.1. Examples
4.1.1.1. State of Matter: Whether it is a solid, liquid, or gas at a given temperature.
4.1.1.1.1. Solid
4.1.1.1.2. Liquid
4.1.1.1.3. Gas
4.1.1.1.4. Changes in States of Matter
4.1.1.2. Color: The appearance of a substance (e.g., copper is reddish-brown).
4.1.1.3. Density: How much mass is in a given volume.
4.1.1.4. Boiling and Melting Points: The temperatures at which a substance changes state (e.g., water boils at 100°C).
4.1.1.4.1. Boiling Point
4.1.1.4.2. Melting Point
4.1.1.5. Solubility: Ability to dissolve in a solvent, like salt in water.
4.1.1.5.1. Soluble vs Insoluble
4.1.1.5.2. Dissolve
4.1.1.5.3. Factors Affecting Solubility
4.1.2. Definition: Characteristics of a substance that can be observed or measured without changing the substance itself.
4.2. Chemical Properties
4.2.1. Definition: Characteristics of a substance that describe its potential to undergo chemical changes or reactions to form new substances.
4.2.2. Examples
4.2.2.1. Toxicity: How a substance affects living organisms chemically.
4.2.2.2. Flammability: Ability to burn or ignite (e.g., gasoline is flammable).
4.2.2.3. Reactivity with Other Substances: How a substance interacts chemically with other substances (e.g., iron reacts with oxygen to form rust).
4.2.2.4. Acidity or Basicity (pH): Whether a substance is acidic, basic, or neutral.
5. Types of Mixtures
5.1. Homogeneous (mixed evenly, like saltwater)
5.1.1. Solutions
5.1.1.1. Solutions are homogeneous mixtures where a solute (like salt) is completely dissolved in a solvent (like water).
5.1.1.2. Characteristics of Solutions
5.1.1.2.1. Particles are so small they cannot be seen, even under a microscope.
5.1.1.2.2. Solutions do not separate over time; they stay evenly mixed.
5.1.1.3. Examples: Saltwater, sugar dissolved in water.
5.2. Heterogeneous (not mixed evenly, like trail mix).
5.2.1. Colloids
5.2.1.1. A colloid is a heterogeneous mixture with small particles spread throughout another substance.
5.2.1.2. Characteristics of Colloids
5.2.1.2.1. Particles are small but can sometimes be seen under a microscope.
5.2.1.2.2. Colloids do not settle over time, so they remain mixed.
5.2.1.2.3. They often look uniform like solutions but can show the Tyndall effect (scattering of light).
5.2.1.3. Examples: Milk & fog
5.2.1.4. Why a Colloid is Heterogeneous:
5.2.1.4.1. Colloids are considered heterogeneous because the dispersed particles and the substance they’re in remain distinct at a microscopic level.
5.2.1.4.2. Even though they look uniform to the naked eye, the particles don’t dissolve into a single phase as in a true homogeneous mixture (like a solution).
5.2.2. Suspensions
5.2.2.1. Suspensions are heterogeneous mixtures where particles are large enough to eventually settle out over time.
5.2.2.2. Examples: Muddy water, sand in water.
6. Trends in Graphs
6.1. Look for patterns, such as steady increases, decreases, or plateaus, to describe how one variable changes in response to another.
6.2. Example: In a temperature vs. time graph of heating water:
6.2.1. A steady increase in temperature shows the water heating up.
6.2.2. A flat line at 100°C indicates the boiling point, where the temperature remains constant as water turns to steam.