Download - Matter-Properties and Changes
Matter-Properties
and ChangesI will distinguish between physical and chemical properties
I will classify matter by composition: element, compound or mixture
I will identify observable characteristics of chemical reactionsI will explain the fundamental law of conservation of mass
Properties of Matter
I will identify the characteristics of a substance
I will distinguish between physical and chemical properties
I will differentiate among the physical states of matter
Substances Matter that has a uniform and unchanging
composition Aka pure substance
Example 1 Table Salt Always 100% sodium chloride
Example 2 Water H2O
NOT AN EXAMPLE Sea water Samples vary by location Amount of salts, water, dissolved substances
Physical Properties A characteristic that can be observed or
measured WITHOUT changing the sample’s composition
Density Color Odor Taste Hardness Melting point Boiling point
Examples-Physical Properties
Salt (sodium chloride) Forms solid white crystals at room
temperature Unique salty taste
Oxygen Colorless Gas at 25 degrees Celsius Melting point -218 degrees Celsius Boiling point -183 degrees Celsius Density 0.0014 g/cc
Extensive Properties
Dependent upon the amount of substance present
Examples Mass Volume Length Weight
Intensive Properties Independent of the amount of the
substance present Examples
Chemical Properties
The ability of a substance to combine with or change into one or more other substances
And/Or The inability of a substance to change into
another substance Example
Iron forms rust when combined with air Iron + Nitrogen (at room temperature) = no
chemical change
Observing Properties of Matter Every substance has its own unique set of physical and
chemical properties May vary depending on conditions of immediate environment
Room temperature, standard pressure, etc.
Example
Copper
Physical Properties Chemical PropertiesReddish brownShinyMalleable (easily shaped)Ductile (drawn into wire)Conducts heat/electricityDensity 8.92 g/ccMelting Point 1085 ℃Boiling Point 2570 ℃
Forms green copper carbonate compound when in contact w/ moist air
Forms new substances when combined with nitric and sulfuric acids
Forms a deep blue solution when in contact with ammonia
States of matter Solid Liquid Gas Plasma
FUN FACT: (only occursnaturally on Earth in the form of lightening bolts!)
PHYSICAL PROPERTY!!!!!
Solids A form of matter that has its
own definite shape and volume. Examples
Wood Iron Paper Sugar
Particles are VERY tightly packed
Will only expand SLIGHTLY when heated
Does NOT conform to shape of container
Incompressible Volume stays the same Example
Wax (moldable) but volume doesn’t change
Liquids
A form of matter that flows, has constant volume, and takes the shape of its container
Examples Water Blood Mercury
Virtually incompressible
Tend to expand when heated
Liquid Particles NOT rigidly held in place less closely packed than
solids Are able to move past each
other
Gases A form of matter that flows
to CONFORM to the shape of its container and fills the ENTIRE volume of its container
Examples Neon
Lighted signs Methane
Cooking Air
Mixture of gases
Particles are VERY far apart
EASILY compressed
A substance NATURALLY in the gaseous state at room temperature
RELATED TERMS Vapor
The gaseous state of a substance that is a SOLID or LIQUID at room temperature
Example steam
Quick Think
Describe the characteristics that identify a sample of matter as being a substance.
Classify each of the following as a physical or chemical property Iron and oxygen form rust Iron is more dense than
aluminum Magnesium burns brightly
when ignited Oil and water do not mix Mercury melts at -39 ℃
Using what you know about the compressibility of gases, explain why the oxygen in a SCUBA tank is compressed.
Create a table that describes the three common states of matter in terms of their shape, volume, and compressibility.
Quick Think- Check
The sample of matter must have a uniform and unchanging composition to be a substance.
Properties Chemical (rust) Physical (density) Chemical (burning) Physical (mixing) Physical (melting)
point)
Particles of gas are spaced apart and are easily compressed. Therefore, it is possible to put a significant volume of oxygen in the tank, which allows the diver to remain under water longer!Solid Liquid Gas
Definite volume Definite volume Fills volume of container
Definite shape Fills container shape
Takes shape of container
Incompressible Virtually incompressible
Compressible
Changes in Matter
I will define physical change and list several common physical changes
I will define chemical change and list several indications that a chemical change has taken place
I will apply the law of conservation of mass to chemical reactions
Physical CHANGES
Alter a substance WITHOUT changing its composition Might result in dramatically different appearance
(yet leave the composition of the substance unchanged)
Examples Crunching up a piece of aluminum foil Cutting a sheet of paper Breaking a crystal Phase changes (solid, liquid, gas)
Key words of Physical Changes
Bend Grind Crumple Split Crush
Chemical CHANGES
A process that involves one or more substances changing into a NEW substance New substance
Formed in reaction Different compositions — than original substance(s) Different properties — than original substance(s)
Example Fermentation of juice, sugars, and other ingredients
(making wine) Rusting of iron (a chemical combo of iron and
oxygen)
Chemical CHANGES
Commonly referred to as a chemical reaction Reactants
Starting substances Products
New substances
Example Reactants = Iron, Oxygen Product = rust
Key Words of Chemical Changes
Explode Rust Oxidize Corrode Tarnish Ferment Burn Rot
The LAW of Conservation of Mass
Mass is neither created nor destroyed during a chemical reaction
Mass is conserved
Mass of Reactants = Mass of Products
Conservation of Mass Problem
Known Mass mercury (II)
oxide = 10.0g Mass liquid mercury =
9.26g
Unknown Mass formed oxygen =
? g
Mass Reactants = Mass Products
Mercury (II) oxide = Mercury + Oxygen
10.0g = 9.26g + ?
0.740 g of Oxygen formed
Quick Think
Describe the results of a physical change and 3 examples. Repeat with chemical change.
A friend tells you, “because composition does not change during a physical change, the appearance of a substance does not change.” Is your friend correct? Explain WHY?
Solve each of the following In the complete
reaction of 22.99 g of sodium with 35.35 g chlorine, what is the mass of the sodium chloride formed?
A 12.2 g sample of X reacts with a sample of Y to form 78.9 g XY. What way the mass of Y that reacted?
Quick Think-Check
During a physical change a substance is altered but its composition does not change. EX melting, freezing, boiling, bending, tearing
During a chemical change the composition of a substance IS altered. EX color change, odor, temperatures change, formation of gas or solid from a liquid.
The statement is false. Composition doesn’t change but a change in appearance often accompanies a physical change.
58.44g of sodium chloride
66.7 g of Y
Mixtures of Matter
I will contrast mixtures and substances I will classify mixtures as homogeneous or
heterogeneous I will list and describe several techniques
used to separate mixtures
Mixtures
A combination of two or more pure substances
Each pure substance retains its INDIVIDUAL chemical properties
Most everyday matter occurs as mixtures Substances naturally tend to mix It is very difficult to keep things pure
Mixture Examples
Water and Sand
Water Colorless liquid
Sand Grainy solid Doesn’t dissolve in
water
Easily seen as two substances mixed
Water and Table Salt
Water Colorless liquid
Table Salt White crystal solid Dissolves in water
NOT easy to see both substances individually
But if you boiled the water a white residue remains (salt!)
Types of Mixtures
Heterogeneous Doesn’t blend
smoothly throughout Individual substances
remain distinct Examples
Water mixed with sand
Fresh orange juice Pulp + Juice
Pizza Dough + sauce +
cheese + toppings
Homogeneous Constant composition
throughout Always has a single
phase Examples
Water mixed with salt
Cough syrup lemonade
Referred to as SOLUTIONS
Solutions
Gas-Gas EX. Air is primarily a
mixture of nitrogen, oxygen, and argon gases
Gas-Liquid EX. Carbonated
beverages contain carbon dioxide gas in solution
Liquid-Gas Ex. Moist air contains
water droplets in air (which is a mixture of gases)
Liquid-Liquid Ex. Vinegar contains
acetic acid in water
Solid-Liquid Ex. Sweetened powder
drink contains sugar and other solid ingredients in water
Solid-Solid Ex. Steel is an alloy of
iron containing carbon
Separating Mixtures
Filtration A technique that uses a
porous barrier to separate a solid from a liquid
Ex through filter paper Like coffee!
Used to filter heterogeneous mixtures composed of solids and liquids
Distillation A separation technique
that is based on differences in boiling points
A mixture is heated until the substance with the lowest boiling point boils to a vapor that can be condensed into a liquid and collected
Used to filter homogeneous mixtures
Separating Mixtures Crystallization
Technique results in the formation of pure particles of a substance
From a solution containing dissolved particles
Ex rock candy From a sugar solution
Often have to add just a little more than what the solution can possibly hold to get the crystals to come out of solution
Produces HIGHLY PURE solids
Chromatography Technique that
separates the components of a mixture (mobile phase) on the basis of the tendency of each to travel or be drawn across another surface (stationary stage)
EX. Soaking up a liquid with paper towel
Quick Think How do Mixtures and
Substances differ?
Classify each of the following as either heterogeneous or homogeneous mixtures
Orange juice Tap water Steel (blend of iron/carbon) Air Raisin muffin
Applying Concepts
Describe the separation technique that could be used to separate each of the following mixtures
Two colorless liquids A non dissolving solid
mixed with a liquid Red and blue marbles
of the same size and mass