Section 3-3 Section 3.3 Mixtures of Matter Contrast mixtures and substances. substance: a form of...
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Transcript of Section 3-3 Section 3.3 Mixtures of Matter Contrast mixtures and substances. substance: a form of...
Section 3-3
Section 3.3 Mixtures of Matter
• Contrast mixtures and substances.
substance: a form of matter that has a uniform and unchanging composition; also known as a pure substance
• Classify mixtures as homogeneous or heterogeneous.
• List and describe several techniques used to separate mixtures.
Section 3-3
Section 3.3 Mixtures of Matter (cont.)
Most everyday matter occurs as mixtures—combinations of two or more substances.
mixture
heterogeneous mixture
homogeneous mixture
solution
filtration
distillation
crystallization
sublimation
chromatography
Section 3-3
Mixtures
• A mixture is a physical combination of two or more pure substances in which each pure substance retains its individual chemical properties.
• A homogenous mixture is a mixture where the composition is constant throughout.
Homogeneous mixtures are also called solutions.
Examples…
C. Mixtures
• Solution– homogeneous– very small particles– no Tyndall effect
Tyndall Effect
– particles don’t settle– EX: rubbing alcohol
Tyndall Effect: The scattering of light by particles.
Section 3-3
Mixtures (cont.)
• A heterogeneous mixture is a mixture where the individual substances remain distinct.
• mixture is not uniform in composition
• Examples…
C. Mixtures
• Colloid– heterogeneous– medium-sized particles– Tyndall effect– particles don’t settle– EX: milk
C. Mixtures
• Suspension– heterogeneous– large particles– Tyndall effect– particles settle– EX: fresh-squeezed
lemonade
C. Mixtures
• Examples:
– mayonnaise
– muddy water
– fog
– saltwater
– Italian salad dressing
colloid
suspension
colloid
solution
suspension
Section 3-3
Separating Mixtures
• Filtration is a technique that uses a porous barrier to separate a solid from a liquid in a heterogeneous mixture.
• Distillation is a separation technique for homogeneous mixtures that is based on the differences in boiling points of substances.
• Crystallization is a separation technique for homogenous mixtures that results in the formation of pure solid particles from a solution containing the dissolved substance.
Section 3-3
Separating Mixtures (cont.)
• Sublimation is the process of a solid changing directly to a gas, which can be used to separate mixtures of solids when one sublimates and the other does not.
• Chromatography is a technique that separates the components of a mixture on the basis of tendency of each to travel across the surface of another material.
A. A
B. B
C. C
D. D
Section 3-3
A B C D
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Section 3.3 Assessment
Which is NOT a technique for separating a homogenous mixture?
A. crystallization
B. distillation
C. filtration
D. chromatography