September 30, 2014
What measures mass and the space something occupies?
What measurement describes the mass per unit volume of things?
Matter
• Matter is the "stuff" everything is made of. Matter has two characteristics:> Matter has mass> Matter occupies space
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Density
• Density: the mass per unit volume of a substance.
Units: g/cm3 or g/mL
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Example 1: Calculating Density
• The volume of a piece of unknown metal is 88.1 ml. The mass of the metal is 1699.450 g. What is the density of the metal?> Can you identify the metal?
Copyright © 2000 Mary Hebrank, Duke Center for Inquiry-Based Learning, Duke University
• A chunk of Aluminum has a mass of 512 kg. What is the volume of the metal?
September 30, 2014
1 Which of the following is the correct formula for density?
A D=V/m
B D=V*m
C D=m/V
D D=1/m
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Classifying Matter
• Matter can be classified in different ways:> States of matter> Composition
• What are the three (main) states of matter?
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States of Matter
• The three (main) states of matter are> Solid> Liquid> Gas
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States of Matter
Solid Liquid Gas
Shape
Volume
Particle
Movement
Definite shape
Indefinite shape: Shape of container
Indefinite shape: Shape of container
Definite volume
Definite volume
Indefinite volume: volume of container
Fixed, vibrate in place
Slide past one another
Move freely at high speeds
September 30, 2014
2 If a substance has a definite volume but takes the shape of its container, it is best classified as a
A solid
B liquid
C gas
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3 In a _______, the particles move freely.
A solid
B liquid
C gas
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Density of a Solid, Liquid, and Gas
• How would you expect the densities of a solid, liquid, and gas to compare?
• *Will explore in a lab (Lab #2!)
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Classifying Matter by Composition
HeterogeneousHomegeneous
CompoundElement
Matter
MixturePure substance
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Has variable composition
Example: Soda, steel, air
Always has the same composition.
Example: Pure water, aluminum, table salt.
Pure Substance and Mixture
• A mixture is a type of matter that is made up of more than one kind of particle. It contains two or more pure substances.
• A pure substance is a type of matter that is made up of only one kind of particle.
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Pure substances can either be compounds or elements.
• Elements: pure substances that are only made up of one type of atom.> Cannot be broken down into other substances by
chemical means.> Example: Oxygen (O2), aluminum (Al)
• Compounds: pure substances that are made up of two or more types of atoms chemically bonded together.> Always have the same composition. > Example: Water is a compound. H2O. Water always
has 2 hydrogen atoms with 1 oxygen atom.
Br C OO Cl C
H H
H
H
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A mixture can be homogeneous or heterogeneous
• Homogeneous mixture: mixture is the same throughout.> Also called a solution> Example: Dissolve salt in water.
• Heterogeneous mixture: mixture is not uniform throughout. Different regions have different properties.> Example: Sand in water. Some regions contain
more sand.
http://www.askpins.com/pics/12/is-h2o2-homogeneous-or-heterogeneous.jpg
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4 A glass of sugar water is best described as a
A Pure substance
B Mixture
C Element
D Compound
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5 Compounds are an example of a ______ and have ___________
A mixture, variable composition
B pure substance, variable composition
C mixture, same composition
D pure substance, same composition
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Au
C
Li
H2O
CO2
NH3
granite
ocean water
soil
sugar water
air
wine
physical separation
chemical reaction
Classifying Matter by Composition
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Physical and Chemical Properties and Changes
• Physical property: can be observed or measured without changing the chemical nature of the matter.> Extensive property: depends upon the amount of
substance present.– Examples: Volume, mass, length
> Intensive: independent of the amount of substance present.
– Examples: Boiling point, density.• Chemical property: ability of a substance to combine
with or change into other substances.> Example: Combustion of butane
September 30, 2014
Physical and Chemical Properties and Changes
• Physical change: a change in one or more physical properties. Does not change the composition of the substance. > Does not create a new substance.> Examples: Boiling water, mixing sand and water,
tearing a piece of aluminum foil.• Chemical change: a change in the composition of the
substance. A chemical change changes the substance into a different substance or substances.> Examples: Burning sugar to create CO2 and H2O
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physical separation
chemical reaction
Classifying Matter by Composition
• You need a chemical reaction to turn a compound into an element, and vice versa. (chemical change)
• You can physically separate mixtures. (physical change)
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Filtration
• Separate out heterogeneous mixtures• Based on particle size
http://en.wikipedia.org/wiki/Filtration
http://www.konia.com.au/technology_water_filtration.php
http://en.wikipedia.org/wiki/Coffee_preparation#mediaviewer/File:Manual_coffee_preperation.jpg
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Distillation
• Separation of homogeneous mixtures • Based on boiling point
> The substance with the lower boiling point vaporizes (boils and turns into gas) first, then can be condensed (turned back into liquid) and collected.
http://www.ssc.education.ed.ac.uk/bsl/chemistry/distillatione.html
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Chromatography
• Separation of homogeneous mixtures• Based on attraction of molecules in the mixture to
either the mobile phase or stationary phase.
http://www.micromountain.com/sci_diagrams/sci_app/sci_app_pages/ctography_lab_eng.htm
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6 Which of the following separates a mixture by size of particle?
A Filtration
B Distillation
C Chromatography
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7 Which of the following separates a mixture based on boiling point?
A Filtration
B Distillation
C Chromatography
September 30, 2014