Solutions and Solubility

Solutions and Solubility Unit 4 extension

What is a solution? • A solution is a homogeneous mixture of 2 or more substances. • Homogeneous: a mixture that is uniform throughout; the particles are evenly distributed

Parts of a solution • A solution contains at least 2 components: • Solute: the substance being dissolved; example: salt • Solvent: substance doing the dissolving; it is the major component in the solution; example: water

Universal Solvent • Water is known as the universal solvent because so many different substances can dissolve in water. • Are there substances that do not dissolve in water? • Yes! Examples: • Sand • Plastic • Cotton • Rubber

Solutions • A solution can be any 2 phases (solid, liquid, or gas) mixed together • Examples: • Brass: solution of zinc metal (s) dissolved in copper metal (s) • Alloy: solid or liquid mixture of two or more metals • Pop: carbon dioxide (gas) dissolved in water (l) • Vinegar: acetic acid (l) dissolved in water (l)

Identifying the solute and solvent Identify the solute(s) and solvent in each solution. Underline the solute and circle the solvent. Remember: SOLUTE dissolves in a SOLVENT. Ocean Water: salt and water Antifreeze: Water and ethylene glycol Soda pop: syrup, water, and CO2 gas Gold Jewelry: gold and copper Air: Nitrogen, oxygen, other gases Kool-Aid: powder, sugar, and water Sterling Silver: silver and copper

Solubility • Solubility: the maximum quantity of a solute (in grams) that can be dissolved in a given amount of solvent (in grams) at a specified temperature.

Concentration • Concentration: how much solute is in a solution • Concentrated solution: large amount of solute • Dilute solution: a small amount of solute Which solution is more concentrated?

Concentration Unsaturated solution: a solution that can dissolve more solute Saturated solution: a solution in which no more solute can dissolve at the given temperature Supersaturated solution: solution that holds more solute than it normally would at a cooler temperature.

3 Factors that Affect Dissolving Increase surface area makes the solute dissolve more quickly.

3 Factors that Affect Dissolving Stirring: moves dissolved solute away so the rest can interact with the solvent

3 Factors that Affect Dissolving • Increase the temperature (Kinetic Energy): particles move faster and collide more often dissolving solute faster • Most gases become less soluble in water as the temperature increases.

Methods to Separate Mixtures Evaporation or Distillation: Uses boiling points

Methods to Separate Mixtures Magnetism: ideal for separating solids in which one of them has magnetic properties

Methods to Separate Mixtures Centrifuge: uses density where layers are formed based on density of materials

Methods to Separate Mixtures Filtering: separates large particles from smaller ones

Methods to Separate Mixtures • Chromatography: The various components of the mixture travel at different speeds, causing them to separate. • Example: Paper Chromatography

Solutions and Solubility