Transcript Matter_Properties_Change

Matter & Change
A. Describing Matter

Understanding matter begins with
observation


Matter is anything that has mass and
takes up space
Chemistry – the study of matter and
the changes it undergoes
B. Four States of Matter

Solids

particles vibrate but can’t move
around

fixed shape

fixed volume

Virtually incompressible
B. Four States of Matter

Liquids

particles can move
around but are still close
together

variable shape

fixed volume

Virtually incompressible
B. Four States of Matter

Gases

particles can separate and
move throughout container

variable shape

variable volume

Easily compressed

Vapor =
 gaseous
state of a substance that
is a liquid or solid at room
temperature
B. Four States of Matter

Plasma

particles collide with enough energy
to break into charged particles (+/-)

gas-like, variable
shape & volume

stars, fluorescent
light bulbs, TV tubes
II. Properties & Changes in Matter

Extensive vs. Intensive

Physical vs. Chemical
A. Physical Properties

Physical Property

can be observed without changing the
identity of the substance
B. Physical Properties

Physical properties can be described
as one of 2 types:

Extensive Property


depends on the amount of matter
present (example: length)
Intensive Property

depends on the identity of substance,
not the amount (example: scent)
C. Extensive vs. Intensive

Examples:

boiling point
intensive

volume
extensive

mass
extensive

density
intensive

conductivity
intensive
D. Physical Changes


Physical Change

changes the form of a substance without
changing its identity

properties remain the same
Examples: cutting a sheet of paper,
breaking a crystal, all phase changes
D. Phase Changes – Physical
Evaporation =
Liquid -> Gas
Condensation =
Gas -> Liquid


Melting =
Solid -> Liquid
Freezing =
Liquid -> Solid



Sublimation =
Solid -> Gas
Deposition =
Gas -> Solid

E. Chemical Properties

Chemical Property

describes the ability of a substance to
undergo changes in identity
F. Physical vs. Chemical Properties

Examples:

melting point
physical

flammable
chemical

density
physical

magnetic
physical

tarnishes in air
chemical
G. Chemical Changes

Process that involves one or more
substances changing into a new
substance
Commonly referred to as a chemical
reaction
 New substances have different
compositions and properties from
original substances

G. Chemical Changes

Signs of a Chemical Change

change in color or odor

formation of a gas

formation of a precipitate (solid)

change in light or heat
H. Physical vs. Chemical Changes

Examples:

rusting iron
chemical

dissolving in water
physical

burning a log
chemical

melting ice
physical

grinding spices
physical
What Type of Change?




What Type of Change?
III. Classification of Matter

Matter Flowchart

Pure Substances

Mixtures
A. Matter Flowchart
MATTER
yes
Can it be physically
separated?
MIXTURE
yes
Is the composition
uniform?
Homogeneous
Mixture
(solution)
no
PURE SUBSTANCE
no
Heterogeneous
Mixture
yes
Can it be chemically
decomposed?
Compound
no
Element
A. Matter Flowchart

Examples:

graphite
element

pepper
hetero. mixture

sugar (sucrose)
compound

paint
hetero. mixture

soda
solution
B. Pure Substances

Element
composed of identical atoms
 EX: copper wire, aluminum foil

B. Pure Substances

Compound

composed of 2 or more
elements in a fixed ratio

properties differ from those of
individual elements

EX: table salt (NaCl)
C. Mixtures

Variable combination of 2 or more
pure substances.
Heterogeneous
Homogeneous
C. Mixtures

Solution
homogeneous
 very small particles
 particles don’t settle
 EX: rubbing alcohol

C. Mixtures

Heterogeneous
medium-sized to
large-sized
particles
 particles may or
may not settle
 EX: milk, freshsqueezed
lemonade

C. Mixtures

Examples:

Answers:

tea

Solution

muddy water

Heterogeneous

fog

Heterogeneous

saltwater

Solution

Italian salad dressing

Heterogeneous
III. Density Fun

Formula

Simple Calculations

Dimensional Analysis
A. Derived Units
Combination of base units
 Volume – length  length  length
1 cm3 = 1 mL
1 dm3 = 1 L
 Density – mass per unit volume
(g/cm3)

M
D=
V
Broken
Heart
M
D V
Density

Density is a physical property of
matter, as each element and
compound has a unique density
associated with it.

The density of any sample of a
substance at the same temperature
will always be the same.
Density

If a substance is more dense than a
liquid it will sink in it, if it is less
dense than it will float

The density of water is 1.00 g/mL,
however this varies slightly with
temperature
B. Density Calculations

An object has a volume of 825 cm3 and a
density of 13.6 g/cm3. Find its mass.
GIVEN:
WORK:
V = 825 cm3
D = 13.6 g/cm3
M=?
M = DV
M
D V
M = (13.6 g/cm3)(825cm3)
M = 11,220 g
M = 11,200 g
B. Density Calculations
A liquid has a density of 0.87 g/mL. What
volume is occupied by 25 g of the liquid?
GIVEN:
WORK:
D = 0.87 g/mL
V=?
M = 25 g
V=M
D
M
D V
V=
25 g
0.87 g/mL
V = 28.7 mL = 29 mL
B. Density Calculations
You have a sample with a mass of 620 g and
a volume of 753 cm3. Find its density.
GIVEN:
WORK:
M = 620 g
V = 753 cm3
D=?
D=M
V
M
D V
D=
620 g
753 cm3
D = 0.82 g/cm3
C. Density Calculations with DA
Used when units do not agree
 Conversions must be made before
using formula

M
D=
V
g
D=
3
cm
C. Density Calculations with DA

You have 3.10 pounds of gold.
Find its volume in cm3 if the
density of gold is 19.3 g/cm3.
cm3
lb
3.10 lb 1 kg 1000 g 1 cm3
2.2 lb
1 kg
19.3 g
= 73.0 cm3
C. Density Calculations with
DA

You have 0.500 L of water.
Find its mass in ounces if
the density of water is 1.00
g/cm3.
L
oz
0.500 L 1000 mL 1 cm3 1.00g 1 kg 2.2 lbs 16 oz
1L
1 mL 1 cm3 1000 g 1kg 1lb
= 17.6 oz
I threw a plastic ball in the pool for
my dog to fetch. The mass of the ball
was 125 grams.
 What must the volume be to have a
density of 0.500 g/mL. ( I want it to
float of course!)


A little aluminum boat (mass of 14.50
g) has a volume of 450.00 cm3. The
boat is place in a small pool of water
and carefully filled with pennies. If
each penny has a mass of 2.50 g,
how many pennies can be added to
the boat before it sinks?
I. Law of Conservation of Mass
Although chemical changes occur,
mass is neither created nor destroyed
in a chemical reaction
 Mass of reactants equals mass of
products

massreactants = massproducts
A+BC

In an experiment 12.36 g of
powdered aluminum is reacted with
23.65 g of iron oxide. If 16.8 g of iron
are produced, what is the mass of the
aluminum oxide produced?