Homogeneous and Heterogeneous Mixtures

Phases of MatterWhat are phases?...andHomogeneous andHeterogeneous MixturesWhat are the distinctions?Use the following keys to control this presentation:control home - starts the show overright arrow (º) advances to the next slideleft arrow (») goes back to the previous slideESC ends the slideshow

PhasesMost people are familiar with the three majorphases, solid, liquid and gas. They may bedistinguished by two properties

PhasesThese two properties are whether they conform! to the shape of the container they are in and! to the total volume of the container.

PhasesThese two properties are whether they conform! to the shape of the container they are in and! to the total volume of the container.The table below summarizes this:phasesolidliquidgasshaperetains shapeconformsconformsvolumeretains volumeretains volumeconforms

Phasesphasesolidliquidgasshaperetains shapeconformsconformsvolumeretains volumeretains volumeconformsSolids retain shape and volume because theiratoms and molecules are in a regular 3D array.

Phasesphasesolidliquidgasshaperetains shapeconformsconformsvolumeretains volumeretains volumeconformsAny phase must at least stay inside thecontainer, but a liquid also retains its volume.The reason is that the molecules stay in contactwith each other most of the time. As the next 2Dfigure illustrates.

Phasesphasesolidliquidgasshaperetains shapeconformsconformsvolumeretains volumeretains volumeconformsThe arrows are meant toconvey that thesemolecules are constantlyrolling around each other,yet staying mostly incontact.

Phasesphasesolidliquidgasshaperetains shapeconformsconformsvolumeretains volumeretains volumeconformsTherefore, the liquidcannot retain its shape.Due to the restraint of theattractions, it cannotchange its volume.

Phasesphasesolidliquidgasshaperetains shapeconformsconformsvolumeretains volumeretains volumeconformsGas molecule do not interact much with eachother and move unrestrained:

PhasesThere may be several phases present at once.There can also be several solid phases of thesame compound. This latter fact is due to thepossibility that different geometrical arrangementcan be created in a 3D array.These considerations will be taken up in thesection “Phase Diagrams”

Homogeneous and Heterogeneous MixturesGenerally mixtures of substances can be classifiedeither as homogeneous or heterogeneous. Thefollowing is a functional definition of these

Homogeneous and Heterogeneous MixturesGenerally mixtures of substances can be classifiedeither as homogeneous or heterogeneous. Thefollowing is a functional definition of these! Homogeneous mixtures are uniform thoughouton a scale corresponding to visible light (400 nm orgreater) . Thus, homogeneous mixtures consist ofa single phase.

Homogeneous and Heterogeneous MixturesGenerally mixtures of substances can be classifiedeither as homogeneous or heterogeneous. Thefollowing is a functional definition of these! Homogeneous mixtures are uniform thoughouton a scale corresponding to visible light (400 nm orgreater) . Thus, homogeneous mixtures consist ofa single phase.! Heterogeneous mixtures are not uniformthroughout. Thus, heterogeneous mixturesgenerally consist of more than one distinct phase.

Homogeneous and Heterogeneous MixturesGenerally mixtures of substances can be classifiedeither as homogeneous or heterogeneous. Thefollowing is a functional definition of these! Homogeneous mixtures are uniform thoughouton a scale corresponding to visible light (400 nm orgreater) . Thus, homogeneous mixtures consist ofa single phase.! Heterogeneous mixtures are not uniformthroughout. Thus, heterogeneous mixturesgenerally consist of more than one distinct phase.The size dividing line between these two is a bitrough with an intermediate types referred to ascolloids.

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