Introduction to Solutions and Solubility SCH 3U

Learning Goals By the end of this lesson students will be able to: Use appropriate terminology related to aqueous solutions and solubility Explain the process of formation for solutions Identify appropriate instruments (e.g., a balance, glassware, titration instruments)

Before we begin, complete the solutions concept map!

What is a Solution Solution- a solution is a homogeneous mixture of two or more substances Homogeneous- means that the mixture is the same all the way through. These mixtures do not settle out. You could take two same-sized samples: one from the bottom and one from the top and they would be the same Heterogeneous- mixture consists of visibly different substances or phases

Solutions Heterogenous Homogeneous Heterogenous Homogeneous

Components of Solutions A solution has two components: The solute The solvent Solvent- is the medium in which a solute is dissolved; the substance in greater amount. It is usually a liquid, although it does not have to be. Example. Water Solute- is a substance that is dissolved in a solventis; the substance in lesser amount. It is usually a solid, although it does not have to be. Most often solutes are solid → think U are solid

Components of Solutions A solution is a particular type of mixture or combination of different substances Each substance retains its chemical properties (they are combined physically, not chemically) The substances can be separated by non-chemical means: filtration, evaporation, separatory funnel, distillation, or centrifugation.

Types of Solutions Both solutes and solvents may be gases, liquids, or solids, producing a number of different combinations. Examples: Solid dissolved in solid Metal in metal produces an alloy: Zinc plus Copper = Brass Gas dissolved in gas Air mixture of O2, N2, CO2, etc. Liquid/Solid/Gas dissolved in a liquid

What type of solution is this?

Explaining Solutions Solutions are created when two substances combine to form a homogeneous mixture. There is a balance between the intermolecular forces and intramolecular forces of the two substances that either allows them to combine, or does not allow them to combine

Intramolecular and Intermolecular Forces Intramolecular Forces - a specific attraction within a molecule Ex. Ionic bonds, covalent bonds and polar covalent bonds Intermolecular Forces - an attraction between molecules Ex. Hydrogen bonding, Dipole-dipole bonding, London Dispersion forces

Explaining Solutions Solids dissolves in liquid: Soluble- If solid can dissolve in liquid Insoluble- If solid cannot dissolve in liquid Liquids dissolved in liquid: “LIKE DISSOLVES IN LIKE” Miscible- If liquids can dissolve in each other Polar compounds will dissolve in polar solvents. Ex. Ethanol and Water (polar) Immiscible- If liquids cannot dissolve in each other Polar compounds will not dissolve in non-polar solvents. Ex. Oil (nonpolar) and Water (polar)

Remember A substance is polar if it : a) has polar covalent bonds (△EN 0.5 - 1.7), and b) has an asymmetrical shape

Homework Watch the video below Complete “Types of Solution” worksheet