Transcript Explain the difference between extensive and intensive physical properties.

1.
Explain the difference between extensive
and intensive physical properties.
2.
Give an example of each.
3.
What are the 5 states of matter?
 Matter
anything that takes up
space & has mass.
◦ Mass amount of matter in an
object.
◦ Volume the space an object
takes up
 Substance-
a particular kind of
matter - pure
 Mixture- more than one kind of
matter
 Solid-
can not flow & has
definite volume.
 Liquid-
definite volume but
takes the shape of its
container (flows).
 Gas-
an indefinite volume and
shape & can flow.
 Vapor-
a substance that is
currently a gas but normally is
a liquid or solid at room
temperature.
 Plasma-
high temperature
physical state of matter in
which atoms lose their
electrons.
◦ Found in fluorescent bulbs.
States of Matter
Definite Definite Temp.
ComVolume? Shape? increase pressible?
Solid
Liquid
Gas
YES
YES
NO
YES
Small
Expans.
NO
NO
Small
Expans.
NO
NO
Large
Expans.
YES

Physical Properties- can be observed &
measured without changing substance.
◦ Examples: odor, color, volume, state, density, melting
point, boiling pt, etc.

Chemical Properties- can only be observed by
changing type of substance.
◦ Examples: flammability, ability to corrode, toxicity,
etc.
Extensive property: depends on
size of sample
- mass, volume, length
Intensive property: independent of
sample size
- density, color, melting or
boiling point
Density- is the ratio of the mass of an object to
its volume.
Density=Mass/Volume
Always remember 1ml = 1 cm3
Density = mass / Volume
Density= 100g / 20cm3
= 5g/cm3
intensive
Density is an ________________
physical property.


As the temperature of a substance increases
the density will ________________
decreases
Why does hot air rise?
◦ Because hot air is less dense than cold air
 Remember that when heat is added more space is
added between the molecules/atoms



The density of water is always
very close to 1 g/mL
If an object’s density is
greater than 1g/mL what will
happen to it when placed in
water?
What if the object’s density is
less than 1 g/mL?
1.
2.
3.
Calcium has a density of 1.54 g/cm3. If you
have 84.3g of calcium, what is the volume?
I have a mass of 74.1g of cobalt. What is the
density if I have a volume of 8.63cm3?
A sample of gold has a density of
166.7g/cm3 & a volume of 8.63cm3. What
is the sample’s mass?
Zeros between other nonzero digits are
significant. (50.3 has 3 sig figs)
2.
Zeros in front of nonzero digits are not
significant. (0.892 has 3 sig figs)
3.
Zeros that are at the end of a number and also to
the right of the decimal are significant (57.00 has
4 sig figs)
(Zeros at the end are significant only if there is a
decimal - 100 has 1 sig fig)
4. All numbers in scientific notation are significant.
1.

1. Convert the 3 practice density problems to
correct number of sig figs







1.009
.0678
800
204.135 – 65.4
870 + 4.674
2.03 x 5.0090
200/ 45.00
1.
2.
Calcium has a density of 2.86 g/cm3. If you
have 84.3g of calcium, what is the volume?
I have a mass of 74.1g of cobalt. What is the
density if I have a volume of 3.68cm3?
 Physical
Changes- changes in state of
matter (melting, boiling, crumpling,
dissolving…) does not change identity of a
substance
◦ H2O (s)--> H2O (l)--> H2O (g)
All Physical Changes!
Condense
Freeze
Evaporate
Melt
Solid
Liquid
Gas
 Chemical
Changes- changes in the
identity of a substance, forms NEW
products.
 Ex. decomposition of water into
Hydrogen and Oxygen
◦ 2 H2O (l)2H2(g) + O2(g)
1.
Combustion
Ex. Using wood or natural gas to heat your house.
2.
Fermentation
Ex. Yeast converts sugar in dough to CO2 and ethyl
alcohol.
3.
Electrolysis
Ex. Water is separated into hydrogen and oxygen.
4.
Oxidation
Ex. Rusting, tarnishing
5.
Metabolism
Ex. Digestion, respiration, etc.






Change in Energy (heat or light)
Production of a gas
Formation of a precipitate
Unexpected Color change
Formation of water
Production of an odor
Classification - State whether each of the
following changes would be physical or
chemical.
1.
2.
3.
4.
5.
6.
melting ice
burning wood
breaking glass
painting wood
Cooking
burning propane
1.
2.
3.
4.
5.
6.
physical
chemical
physical
physical
chemical
chemical
For each of the following put P for Physical
change and C for Chemical change.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
____
____
____
____
____
____
____
____
____
____
Melting ice
Baking a cake
Burning a candle
Dissolving salt in water
Rusting iron
Mixing baking soda and vinegar
Bending wire
Making wine
Grinding stone
Beating an egg
Mass can not be created or destroyed
in ordinary (not nuclear) chemical
changes.
 Mass of reactants = Mass of products

2 NaCl + MgBr2
 2 NaBr + MgCl2
15 grams + 10 grams =
8 grams +
?
Matter
Pure
Substances
Compounds
Elements
Mixtures
Homogeneous (solutions)
Heterogeneous
 Mixture-
consist of a physical
blend of two or more
substances. (has variable
composition)
 Pure
Substance- a type of matter
with unchanging composition.
 Can be a compound or an element
 Homogeneous
Mixture - same
form, a solution, single phase,
appears uniform throughout
(milk, wine, sea water, salt
water…)
 Heterogeneous
Mixture different form, does not appear
to be uniform (oil slick on the
ocean, soup…)



Homogeneous mixture
Mixed molecule by molecule
Can occur between any state of matter.
◦
◦
◦
◦
◦
Solid in liquid- Kool-aid
Liquid in liquid- antifreeze
Gas in gas- air
Solid in solid – brass – an ALLOY
Liquid in gas- water vapor
 Like
all mixtures, they keep
properties of their
components.
 Mixtures
can be separated by
physical means unlike
compounds

Filtration

Distillation

Crystallization

Chromatography
◦ Use of a porous barrier to remove solids from liquids
◦ Separation of homogeneous mixtures based on
difference in boiling points
◦ Solid particle formed from supersaturated solution
(rock candy)
◦ Uses a mobile and stationary phase to separate
components (dyes from ink)
 Elements-
Can Not Be Broken Down
by Chemical Means -Represented by
the Periodic Table (N, H, O …)
 Compounds-
Can be broken down by
chemical means into constituent
elements (H2O, CO, CO2 …)
Compound
Mixture
One kind of pieceMolecules
More than one kind Molecule or atoms
Making is a
chemical change
Making is a
physical change
Only one kind
Variable composition
Element
Compound
Mixture
Have your Vocab. for the Matter Unit and
Notebooks out for me to check
1.
Give 2 indicators of a chemical change.
2.
Give an example of a physical change.
3.
What type of change is required to break
down a compound – physical or chemical?
a
compound is always
composed of the same
elements in the same
proportion by mass.
% by mass = mass of element
mass of compound
x 100
 when
different compounds are
formed by a combination of same
elements, different masses of one
element combine with same
relative mass of other element in
a ratio of small whole numbers.