mixtures and solutions
DESCRIPTION
Mixtures and Solutions. Get seated. Get out notebooks and begin notes. Mixtures and Solutions. A mixture is a combination of two or more components that are NOT chemically combined, and retain their identities. - PowerPoint PPT PresentationTRANSCRIPT
Mixtures and Solutions
Get seated. Get out notebooks and begin notes.
Mixtures and Solutions
• A mixture is a combinationof two or more components thatare NOT chemically combined,and retain their identities.
Mixtures can be physically separated. The identities of the substances DO NOT change.
A homogeneous mixture is also called a
solution.
Mixtures• When a mixture’s components are easily
recognizable, such as pizza, it is called a heterogeneous mixture.
• In a homogeneous mixture such
as chocolate milk, the component particles cannot be distinguished,
even though they still retain their
original properties.
Mixtures• Common Techniques for Separating Mixtures
Distillation – separates a mixture based on boiling points of the component.
Examples :saltwatercrude oil into gasoline and kerosene
Magnet – separates iron from other objects.
Centrifuge – spins and separates according to densities.
Solutions• A mixture that appears to be a single
substance but is composed of particles of two or more substances that are distributed evenly amongst each other.
A solution may be liquid, gaseous, or solid.Examples of solutions
Liquid - seawaterGas - airSolid - alloys
Parts of a Solution•SOLUTE – the part of a solution that is being dissolved (usually the lesser amount)•SOLVENT – the part of a solution that dissolves the solute (usually the greater amount)•Solute + Solvent = Solution
Solute
liquid
Solvent
solid
Example
Mercury in gold,
Hexane in wax
solid solid Steel, Brass’
Alloys,
gas solid Hydrogen into metals
solid liquid Sugar, Salt, Tea, Kool-Aide
liquid liquid Mixed drinks, Paint thinners.
gas liquid Soft drinks****, oxygen in water.
gas Gas Air
Solutions• Dissolving – The process in which
particles of substances separate and
spread evenly amongst each other.• Solute – substance that is dissolved. A solute is
soluble, or able to dissolve. • A substance that is insoluble is unable to dissolve, forms a mixture that is not homogeneous, and therefore NOT a solution.
• Solvent – substance in which solute is dissolved.
DefinitionsDefinitionsSolutions can be classified as Solutions can be classified as
saturatedsaturated or or ununsaturated or saturated or super-saturatedsuper-saturated..
A A saturatedsaturated solution contains the solution contains the maximum quantity of solute that maximum quantity of solute that dissolves at that temperature.dissolves at that temperature.
An An unsaturatedunsaturated solution contains solution contains less than the maximum amount less than the maximum amount of solute that can dissolve at a of solute that can dissolve at a particular temperatureparticular temperature
9
DefinitionsDefinitions
SUPERSATURATED SOLUTIONSSUPERSATURATED SOLUTIONS contain more solute than is contain more solute than is possible to be dissolvedpossible to be dissolved
Supersaturated solutions are Supersaturated solutions are unstable. The supersaturation is unstable. The supersaturation is only temporary, and usually only temporary, and usually accomplished in one of two ways:accomplished in one of two ways:
1.1. Warm the solvent so that it will Warm the solvent so that it will dissolve more, then cool the dissolve more, then cool the solution solution
2. Evaporate some of the solvent carefully so that the solute does not solidify and come out of solution.
Solubility
• The solubility of a solute is the amount of solute needed to make a saturated solution using a given amount of solvent at a certain temperature.
• Solubility is usually expressed in grams of solute per 100 ml of solvent (g/100ml)
• Three (3) methods that affect solubility– Mixing, stirring, or shaking– Heating– Crushing or grinding
Suspension
• A mixture in which particles ofa material are dispersed through-out a liquid or gas but are largeenough that they settle out.
– Particles are insoluble, so they DO NOT dissolve in the liquid or gas.
– Particles can be separated using a filter.• Examples:• Salad dressing• Medicines that say“shake well before use”
Colloids• A mixture in which the particles are
dispersed throughout but are not heavy enough to settle out.
• Made up of solids, liquids and gases.– Examples :
• Mayonnaise• Stick deodorant• Milk• Jello• Whipped cream• Peanut butter
My Quickie Definitions
• Unsaturated – Can hold some more
• Saturated – Can’t hoolllddd nooo moorre
• Super-saturated – Found a way to make it hold more
• Solubility – ability to be dissolved