Chapter 1/2Chemistry and Matter

What is Chemistry?

Chemistry is the study of matter and the changes that matter undergoes.

 

Because all things are made up of matter, chemistry affects all aspects of life.

Areas of Chemistry

Organic Chemistry

Inorganic Chemistry

Biochemistry

Analytical Chemistry

Physical Chemistry

The Scientific Method

Making Observation (leads to a question)

Developing a Hypothesis

Experiment (Test Hypothesis)

Conclusion (Develop Theory or Scientific Law)

Repeat experiment

Matter

Matter: Anything that takes up space and has mass (inertia)Mass: The measure of the amount of matter that an

object containsProperties of Matter: Describes the characteristics

and behavior of matter, including the changes that matter undergoes

 

Matter

The Macroscopic View of MatterMatter that is large enough to be seen

The Submicroscopic View of MatterSo small that you cannot see it, even

with the most powerful microscope

The Microscopic View of MatterSmall enough that a microscope is

needed.

Extensive vs. Intensive

An extensive property is a property that depends on the amount of matter in a sample.Ex. Mass, volume, length, etc.

An intensive property is a property that depends on the type of matter in a sample, not the amount of matter.Ex. Color, Texture, density, etc.

Observations of matter

Qualitative: made without measurementEx. Color, texture, shape, etc.

Quantitative: made with measurementEx. Mass, volume, length, etc.

States of Matter

Solid: a form of matter with definite shape and volume

Liquid: a form of matter with a indefinite shape, but a definite volume

Gas: a form of matter with an indefinite shape and volume

SOLID LIQUID GASFreezing

Evaporation

Melting

Sublimation

Condensation

MixturesMixture: A combination of two or more

substances in which the basic identity of each substance is not changed.

Mixtures can be classified as heterogeneous or homogeneous

Heterogeneous Mixtures: A mixture that has a composition that is different throughout.Ex. Cookie Dough ice cream

Homogeneous Mixtures: A mixture that has a composition that is the same throughout.Ex. Lemonade (solutions)

Solutions

A solution is made up of a solute and a solvent

Solute: The substance being dissolved

Solvent: The substance doing the dissolving

When the solvent is water the solution is said to be ‘AQUEOUS” (an aqueous solution.)

SOLUTE + SOLVENT = SOLUTION

SUGAR + WATER = AQUEOUS SUGAR

SOLUTION

Separating MixturesDifferences in Physical

properties can be used to separate mixtures.

Filtration: a process that separates a solid from a liquid in a heterogeneous solution.

Distillation: A liquid is boiled to produce a vapor which is then condensed into a liquid (used to separate a liquid from solids or to separate two liquids)

Elements vs. Compounds

Element: simplest form of matter that has a unique set of properties.

Compound: substance that contains two or more elements chemically combined

Compounds can be broken down into simpler substances by chemical means, elements cannot.

Symbols

Chemists use chemical symbols to represent elements, and chemical formulas to represent compoundsEx. Sodium = Na, Chlorine = Cl Ex. Sodium Chloride = NaCl

MATTER

Matter

MIXTURES PURE SUBSTANCES

COMPOUNDSHOMOGENEOUSMIXTURES ELEMENTSHETEROGENEOUS

MIXTURES

PHYSICAL CHANGES

DIRT, BLOOD, MILKSODA, GASOLINE,

AIR

SALT, BAKING SODA,SUGAR

OXYGEN, GOLD,IRON

Density

The amount of matter (mass) contained in a unit volume.

DENSITY =

MASS per VOLUME

-OR-

GRAMS PER MILLILITER

VOLUME

Measured in grams

Measured in milliliters

DENSITY =

MASS

Chemical vs. Physical Changes

Physical Property: a quality or condition of a substance that can be observed or measured without changing the substance’s composition Ex. Solubility, melting point, boiling point,

color, density, electrical conductivity, and physical state (solid, liquid, gas)

During a physical change, the composition of matter always remains the same. Tearing, cutting, grinding Change of state: boil, freeze, melt, and

condense

Chemical vs. Physical Changes

Chemical Property: the ability of a substance to undergo a chemical change is called a chemical property Ex. Flammable, corrosive, ability to rust

During a chemical change, the composition of matter always changes Ex.. burn, rot, rust, decompose, ferment,

explode, corrode A chemical change is also called a chemical

reaction. Possible indicators of a chemical change

include: a transfer of energy a change in color the production of gas or the formation of a precipitate

Chemical Reactions and Energy

Energy the capacity to do work

All chemical changes involve some sort of energy change.

Energy is either given off ….“EXOTHERMIC”

Or….taken in…. “ENDOTHERMIC” 

Law of Conservation of Mass and EnergyThe law of

conservation of mass and energy states that both matter and energy cannot be created or destroyed in any process

IT’S THE LAW!!!

Energy

Energy is the capacity to do work or produce heat

Kinetic Energy: Energy of Motion

Potential Energy: Energy of Position (stored energy)