What is a solution?

Solution A solution is a homogeneous mixture of two or more components. The dissolving agent is the solvent. The substance which is dissolved is the solute. The components of a solution are atoms, ions, or molecules, which makes them m or smaller in diameter (not visible to the naked eye).

Identify the Solvent and Solute

Suspensions The particles in suspensions are larger than those found in solutions. Components of a suspension can be evenly distributed by a mechanical means, like by shaking the contents, but the components will settle out. These are HETEROGENOUS mixtures

Suspensions Flour suspended in water Sand settling out of water

Colloidal Suspensions Particles intermediate in size between those found in solutions and suspensions can be mixed such that they remain evenly distributed without settling out. The mixture they form is called a colloidal dispersion.

Colloidal Examples milk paint Jell-O

Separation Techniques Decanting  Separates liquid from solid Centrifugation  Separates substances based on density  Centrifuge spins rapidly and denser substances collect at bottom

Distillation  Separates mixture based on different boiling points of the parts  As each part of mixture boils, the gas rises and enters the condenser where the substance becomes a liquid and can be collected

Separation Techniques Filtration  Separate solid from liquid using a filter Evaporation  Allow solvent to evaporate, leaving the solute behind

Chromatography Means “color writing” Separates mixtures based on attraction Different parts of the mixture are more attracted to the solvent or the paper

Mixtures are NOT always liquids! Solid in solid: ex. SAND Solid in liquid: ex. MUDDY WATER or BLOOD Solid-gas: SMOKE & AIR POLLUTION Liquid in gas: FINE MIST – AEROSOLS Gas in Liquid: SODA Gas in gas: AIR

How does a solution form? When the solute and solvent are attracted toe ach other with a force greater than the intermolecular forces holding together the pure solute and pure solvent “like dissolves like” – common phrase really means that substances with similar intermolecular attractive forces will be attracted to each other and most likely will dissolved

Water is the universal solvent…really? Water does dissolve many substances; polar and ionic substances usually dissolve in water because of the ion-dipole or dipole-dipole interactions. Hydrated – term used when water is the solvent Solvation – term used to describe when other substances act as the solvent Salt Dissolving in Water Animation

How much solute dissolves in a given solvent? Solubility refers to the maximum amount of solute that can dissolve in a given solvent