September 30, 2014
Matter
• Matter is the "stuff" everything is made of. Matter has
two characteristics:
> Matter has mass
> Matter occupies space
What measures mass and the space
something occupies?
What measurement describes the mass
per unit volume of things?
September 30, 2014
Density
• Density: the mass per unit volume of a substance.
Units: g/cm3 or g/mL
September 30, 2014
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?
• A chunk of
Aluminum has a
mass of 512 kg.
What is the
volume of the
metal?
Copyright © 2000 Mary Hebrank, Duke Center for Inquiry-Based Learning, Duke University
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
September 30, 2014
Classifying Matter
• Matter can be classified in different ways:
> States of matter
> Composition
• What are the three (main) states of matter?
September 30, 2014
States of Matter
• The
>
>
>
three (main) states of matter are
Solid
Liquid
Gas
September 30, 2014
States of Matter
Solid
Shape
Definite
shape
Liquid
Gas
Indefinite
shape: Shape
of container
Indefinite
shape: Shape
of container
Volume
Definite
volume
Definite
volume
Indefinite
volume: volume
of container
Particle
Fixed,
vibrate
in place
Slide
past one
another
Move freely
at high
speeds
Movement
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
September 30, 2014
3 In a _______, the particles move freely.
A solid
B liquid
C gas
September 30, 2014
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!)
September 30, 2014
Classifying Matter by Composition
Matter
Pure substance
Element
Mixture
Compound
Homegeneous
Heterogeneous
September 30, 2014
Pure Substance and Mixture
• A pure substance is a type
of matter that is made up of
only one kind of particle.
• 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.
Always has the
same composition.
Example: Pure
water, aluminum,
table salt.
Has variable
composition
Example: Soda,
steel, air
September 30, 2014
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.
H
H
Br
O
C
O
Cl
C
H
H
September 30, 2014
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
September 30, 2014
4 A glass of sugar water is best described as a
A Pure substance
B Mixture
C Element
D Compound
September 30, 2014
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
September 30, 2014
Classifying Matter by Composition
physical separation
chemical reaction
Au
H2O
C
CO2
Li
NH3
sugar
water
granite
air
ocean
water
wine
soil
September 30, 2014
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
September 30, 2014
Classifying Matter by Composition
physical separation
chemical reaction
• You need a chemical reaction to turn a compound into
an element, and vice versa. (chemical change)
• You can physically separate mixtures. (physical change)
September 30, 2014
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
September 30, 2014
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
September 30, 2014
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
September 30, 2014
6 Which of the following separates a mixture by size
of particle?
A Filtration
B Distillation
C Chromatography
September 30, 2014
7 Which of the following separates a mixture based
on boiling point?
A Filtration
B Distillation
C Chromatography
September 30, 2014