Mixtures
 Mixture: a combination of two or more substances that are
not chemically combined.
 Can only become a mixture if they do not react to form a
compound.
 There are no chemical changes that happen in a mixture.
 In some mixtures you can see the components (ex. Pizza)
and in others you cannot (ex. Salt water)
Separating Mixtures
 Distillation: a process that separates a mixture based on
the boiling points of the components.
 Magnets: used to separate different metals based on their
physical properties.
 Centrifuge: a way of separating mixtures into their
components by their densities.
 Evaporation: A way of separating mixtures by using a
change of state from a liquid to a gas.
Comparing Mixtures and
Compounds
Mixtures
Compounds
Made of elements, compounds, or both
Made of elements
No change in original properties of
components
Change in original properties of
components
Separated by physical means
Separated by chemical means
Formed using any ratio of components
Formed using a set ratio of components
The Ratio of Components in a
Mixture
 Components of a mixture do not need to be mixed in a
definite ratio.
 Ex. Granite: Made from feldspar, mica, and quartz minerals.
Feldspar is pink. Mica is black. Quartz is clear. Can you
explain the difference in these?
Solutions
 Solution: a mixture that appears to be a single substance.
 They are composed of particles of two or more substances
which are distributed evenly among each other.
 Have the same appearance and properties throughout the
mixture.
Solutions Cont.
 Dissolving: the process in which particles of substances
separate and spread evenly throughout the mixture.
 Solute: The substance that is dissolved.
 Solvent: the substance in which the solute is dissolved.
 Soluble: means a substance is “able to dissolve.”
 Insoluble: means a substance is “unable to dissolve.
Soluble & Insoluble
 A substance that is soluble will dissolve into a solute and
become a solution.
 A substance that is insoluble will not dissolve into a
solute and will become a mixture.
Which is the solvent? Which is the
solute?
 When a solid dissolves into a liquid: the solid is the solute
and the liquid is the solvent.
 When two liquids or gasses form a solution: The substance
that is present in the largest amount is the solvent… the
other then, must be the solute.
Examples of Different States in
Solutions
States
Examples
Gas in gas
Dry air (oxygen in nitrogen)
Gas in liquid
Soft drinks (carbon dioxide in water)
Liquid in liquid
Antifreeze (alcohol in water)
Solid in liquid
Salt Water (salt in water)
Solid in solid
Brass (zinc in copper)
Particles of Solutions
 Particles in solutions are so small they never settle out.
 They cannot be removed by filtering.
 Particles are so small they don’t even scatter light.
Concentration of Solutions
 Concentration: a measure of the amount of solute
dissolved in a solvent.
 Can be expressed as grams of solute per milliliter of solvent.
(g/ml)
 Dilute: a solution with less solute.
 Concentrated: a solution with more solute.
 Dilute and Concentrate do not tell you how much solute is
has been dissolved. They can only compare.
Solubility
 Solubility: the ability of the solute to dissolve in a solvent
at a certain temperature.
Dissolving gases in liquids
 Gases become less soluble in liquids as the temperature is
raised.
 Ex. Pop becomes “flat” in warm temperatures because
gasses cannot stay dissolved in warmer temperatures.
Dissolving Solids Faster in Liquids
 Mixing: by stirring or shaking causes the solute particles
to separate from one another and spread out more quickly
among the solvent particles.
 Heating: Causes particles to move more quickly. The
solvent particles can separate the solute particles and
spread them out more quickly.
 Crushing: The solute increases the amount of contact it
has with the solvent. The particles of the crushed solute
mix with the solvent more quickly.
Suspensions & Colloids
 Suspension: a mixture in which particles of a material are
dispersed throughout a liquid or gas but are large enough
that they settle out.
 Ex. Snow Globe
 Colloid: a mixture in which the particles are dispersed
throughout but are relatively small and are fairly well
mixed.
 Ex. Milk, mayonnaise, stick deodorant