Transcript Matter and Change

Matter and Change
Matter
Matter-anything that has mass and takes up space.
Volume-the measure of the amount of space an
objects takes up
Mass  Weight
Mass-the measure of the amount of matter that makes
an object
- mass is a constant, it will not vary
Weight – the measure of the force of gravity on an
object.
- weight can and will vary with changes in gravity
Law vs. Theory
Scientific Law (Natural Law) – summary of
observed, measurable behavior that occurs
repeatedly and consistently.
- often expressed with mathematical
equations
- describes what happens, but does not
attempt to explain why
Theory – explains scientific laws, open to
debate, not always consistent, evolve over
time as scientists observe more
Describing Matter - States
Kinetic Theory of Matter – all matter is made of tiny
constantly moving particles.
Kinetic Energy (KE) – energy with motion
Solid - matter with a definite shape and volume.
-very tightly packed particles, almost incompressible
-expand only slightly when heated
-low KE
Liquid - matter that has a definite volume but no definite
shape.
-almost incompressible particles
-tend to expand when heated
-moderate KE
Describing Matter - States
Gas - matter with no definite shape or volume
-particles are spaced very far apart,
easily compressed
-completely fill to take the shape and volume
of any container
-high KE
Liquids and gases are both considered fluids.
Fluid – any substance made of particles that can
flow over and around each other.
Describing Matter - States
GAS  VAPOR
When a substance is referred to as a gas, it is
understood that is a gas under normal condition
of temperature and pressure.
A vapor refers to a substance that is normally a
solid or liquid and has changed into the gas
state.
I2

Solid
I2
Gas
Iodine
Vapor
Sublimation
Describing Matter - States
Plasma – gas like state of matter with negatively
charged particles
-matter with no definite shape or volume
- found in areas of extremely high temperatures
-particles are spaced very far apart, easily
compressed
-extremely high KE
Describing Matter - Properties
Physical Properties - properties that can be observed
or measured without changing the substances
composition.
Color
State
Size
Shape
Texture
Density
Melting point
Boiling point
Solubility
Describing Matter - Properties
Chemical Property - the ability of a substance to
undergo a chemical reaction
- can ONLY be observed or measured WITH changing
the composition of the substance
Reacts violently with water
Reacts with oxygen to form rust
Produces hydrogen gas
Describing Matter - Changes
Physical Change - a change in matter that
does NOT results in the chemical
composition being changed
Changes in
Size, Shape or STATE of MATTER
Solid
Evaporation/Vaporization/Boiling
KE Increases
Liquid
Gas
Condensation: KE Decreases
Describing Matter - Changes
Chemical Change - a change in matter that results in the
chemical composition being changed
Clues of a chemical change/reaction:
 release of a gas
BOILING
- look for bubbles

release of heat, light, sparks or sound
- release of energy

formation of a precipitate
- precipitate – solid formation as a result of a chem change

color change
- permanent change in color


change in odor
change in temperature
- increase or decrease
FREEZING
Chemical Reactions
Chemical reaction - a process when one or more
substances turn into new substances
Fe + O  FeO
iron + oxygen  iron oxide
Reactants - starting substances
- always written to the left of the yield sign ()
- 2 or more reactants are separated by a plus sign (+)
Products - substances formed
- always written to the right of the yield sign ()
- 2 or more products are separated by a plus sign (+)
Chemical Reactions
Law of conservation of matter – during any change
(physical or chemical) mass is not created or
destroyed, it is conserved.
- “conserved” – the same before & after
- mass is not lost or gained
- the total mass of the reactants is the same as the
total mass of the products
Chemical Reactions
What is the mass of lithium chloride produced if 9.9g of
lithium reacts with 3.4g of chlorine?
Lithium + Chlorine  Lithium Chloride
9.9g + 3.4g

?
13.3g
32.5g of magnesium reacts with 27.8g of zinc nitrate to
produce 43.8g of magnesium nitrate and zinc. What is
the mass of zinc produced?
Magnesium + Zinc  Magnesium +
Nitrate
Nitrate
32.5g
+
27.8g

43.8g
+
Zinc
?
16.5g
Classification of Matter
Matter is classified into 2 main categories:
Matter
 anything with mass & volume
Pure
Substances
Mixtures
Classification of Matter
Pure Substances - any matter with a uniform
composition
Two Types of Pure Substances:
1. Element - the simplest form of matter that
can exist under normal laboratory
conditions
-cannot be separated
-building blocks for all other substances
Classification of Matter
Atomic Models of Elements
Sodium (Na)
Chlorine (Cl)
Classification of Matter
Two Types of Pure Substances:
2. Compound - two or more elements chemically
combined
- has a definite ratio
- can only be separated by a chemical process
- properties of a compound are different from the
properties of the elements that make it
Atomic Model of a Compound
Sodium Chloride (NaCl)
Classification of Matter
Properties of a compound are different from the
properties of the elements that make it.
Example:
Sodium (Na) – solid at room temperature that reacts
violently with water
Chlorine (Cl) – poisonous yellow-green gas at room
temperature
Sodium Chloride (NaCl) – white crystalline water
soluble solid used as a food additive
Matter
 anything with mass & volume
Pure
Substances
Mixtures
Elements Compounds
Classification of Matter
Mixture - a physical blend of two or more
substances.
-no definite ratio
-can be separated by a physical change
Atomic Model of a Mixture
Classification of Matter
Two Types of Mixtures:
1. Heterogeneous Mixture
 mixture that is NOT uniform in composition
 parts of mixture are typically easy to identify
 if the mixture is divided up into parts, the
parts would be different from each other
Classification of Matter
Two Types of Mixtures:
2. Homogeneous Mixture
 mixture that is uniformly mixed
 parts of the mixture are not easy to identify
 if the mixture is divided up into parts, the
parts would be the same
 also called a solution
Classify the following as either a homogeneous
mixture or a heterogeneous mixture.
Heterogeneous
Mixture
Heterogeneous
Mixture
Classify the following as either a homogeneous
mixture or a heterogeneous mixture.
Homogeneous
Mixture
Homogeneous
Mixture
Matter
 anything with mass & volume
Pure Substances
Mixtures
Elements Compounds Heterogeneous
Homogeneous
Classification of Matter - Solutions
Solutions are homogeneous mixtures.
They can be solids, liquids or gases.
Two parts of a solutions:
1. Solute
 part of the mixture being dissolved
 present in the smaller amount
2. Solvent
 part of the mixture doing the dissolving
 present in the greater amount
Classification of Matter - Solutions
Saturation
Unsaturated - a solution with LESS than the
maximum amount of solute for a given amount
of solvent
Saturated – a solution with the maximum amount
of solute for a given amount of solvent
Supersaturated – solution that contains more
solute than it should theoretically dissolve
Classification of Matter - Solutions
Concentration
Concentration – a measure of the amount of
solute that is dissolved in a given amount of
solvent
Dilute – contains low amounts of solute
Concentrated – contains high amounts of solute
Aqueous Solutions (aq) – homogeneous
mixtures/solutions in which water is the solvent
Classification of Matter - Solutions
Colligative Properties of Solution
Colligative Properties – a property of a solution
that depends on the number of solute particles
present.
 Freezing Depression – lowering the freezing
point of a substance by adding a solute.
 Boiling Point Elevation - raising the boiling
point of a substance by adding a solute.
Classification of Matter - Solutions
Factors that affect the rate of a SOLID solute
dissolving:
1. Stirring/Agitation – brings fresh solvent in
contact with the solute
2. Temperature - solids typically dissolve better
in warm temperatures
3. Increasing the Surface Area (grinding up into
small pieces) – more solute comes in contact
with the solvent.
Classification of Matter - Solutions
Factors that affect the rate of a GAS solute
dissolving:
1. Temperature - gases typically dissolve better
in cold temperatures
2. Pressure – increasing the pressure increases
the amount of gas that will dissolve in a
liquid solution.
Separating Mixtures
Filtering/Filtration - uses a filter of porous material
to separate a mixture of different sized
components
Decanting – slowly pouring a liquid off a solid
Evaporation - the liquid portion of a solution
changes to a gas or vapor leaving a solid
behind
Separating Mixtures
Distillation - method of separating components of a
solution with different boiling points.
• involves 2 stages, both are state of matter changes
(1) The solution is boiled to vaporize the component of
the solution with the lower boiling point.
(2) The vapor is cooled to turn it back into a liquid
Separating Mixtures
Chromatography - method of separation
used to see what colors make up a
solution
Steps of Chromatography
• Material to be separated
is spotted on
chromatography paper
• Paper is dipped into a
solution that will be
absorbed by the paper
and moves up
• Some colors move more
than others and separate
Separating Mixtures
Solubility – used to separate components of a
mixture when one is soluble in a substance and
one is not
Melting Point - method of separating components of
a mixture with different melting points
Magnetism - used to separate components of a
mixture when one is attracted to a magnet and one
is not