CHEMISTRY IUnit 1

The Science of Chemistry and Matter

What is Chemistry?

POD: Discuss with the person next to you different ways you think chemistry is present in your everyday life and write it down on your pod.

Laboratory

Energy Elements

Compounds

Classification of matterObjectives:

1. Relate chemistry to everyday life.2. Identify traditional areas of study in chemistry.3. Define matter.4. Categorize samples of matter as a mixture or a

substance.5. Distinguish between homogeneous and

heterogeneous mixtures.6. Describe ways components of a mixture can be

separated7. Explain the difference between a compound and

an element.

Chemistry is the study of the composition of matter and the changes matter undergoes. Matter: anything that has mass and occupies

space. There are five traditional areas of study for

chemistry Organic chemistry: study of chemicals containing

carbon. Inorganic chemistry: study of chemicals that do

not contain carbon. Biochemistry: study of processes that take place

in organisms. Analytical chemistry: focuses on composition of

matter Physical chemistry: describes behaviors of

chemistry.

Chemistry far and wide:Materials: plastic, glass, ceramics, perfumes,

food, etc.Energy: fossil fuels, food, solar batteries,

nuclearMedicine: penicillin, aspirin, Vitamin CAgriculture: fertilizer, pesticides, growth

hormonesEnvironment: ozone, carbon dioxide- global

warming, pollutionAstronomy: composition of planets and stars

Classification of matterMixtures: a physical blend of two or more

components. Ex. Salad, pizza, milkshake and air Heterogeneous mixtures: the composition is not

uniform

Homogeneous mixtures: composition is uniform throughout. Also called solutions.

In a solution we have a solute (substance being dissolved) and a solvent (substance dissolving solute)

Water is the universal solvent Most are liquids

Some are solids. Example alloys of different metals like brass, an alloy of copper and zinc.

For tomorrow research what other types of alloys we use.

Some are gases like the air

Figure 1.4a

HOMOGENOUS

MIXTURES

HETROGENOUS

Separation of mixtures• Separate mixtures based on

different physical properties of the components

Centrifugation &Decanting

Density

EvaporationVolatility

ChromatographyAdherence to a Surface

FiltrationState of Matter (solid/liquid/gas)

DistillationBoiling Point

TechniqueDifferent Physical Property

Distillation Filtration

Pure Substances: have fixed composition.Elements are the simplest form of matter

that has its unique set of properties.Ex. Gold is an element. All atoms of gold

have the same properties.Elements are shown in the Periodic Table.There are more than 100 elements, most of

them occur naturally.Elements are represented by one (a capital

letter) or two letter symbols(a capital letter and a lowercase letter).

Ex. C: carbon Co: cobalt

Compounds is a substance that contains two or more elements chemically combined in a fixed proportion.

• Represented by chemical formulas using symbols of elements present in compound and subscripts indicated how many atoms of each element is present.Ex. H2O: water CO: carbon monoxide CO2: carbon dioxide

Figure 1.7b

Learning Check:1. How do elements relate to compounds?

2. How do elements and compounds relate to mixtures?

3. What is the main difference between pure substances and mixtures?

Learning Check:1. How do elements relate to compounds? Compounds

are made from elements chemically combined.

2. How do elements and compounds relate to mixtures?

Elements and compounds physically combine to form a mixture.

3. What is the main difference between pure substances and mixtures?

Pure substances have a fixed composition and the composition of mixtures may vary.

Classwork: p53 #1-3

HW: Bring tomorrow any sample of matter and share with the class how you would classify the sample and why. (Don’t use water as an example, too easy!!)

Changes in matter 1. Identify properties as extensive or intensive.2. Define a physical property and a chemical

property.3. Describe a physical change.4. Describe what happens during a chemical

change.5. Identify clues that a chemical change has

taken place.

Changes in matterPhysical change : same substance remains

after change.Ex. Pounding, cutting, dissolvingChanges of state: melting, boiling, condensing,

etc.

Chemical change: a new substance (different characteristics) appears after the change. (a chemical reaction)Evidence of chemical change

Production of gas (observed as bubbles or change of odor)

Release or absorption of energy (change in temperature or giving off light)

A color change Formation of a precipitate (solid formed when two

clear solutions combine and become cloudy)Ex. Burning, digestion, fermentation During a chemical reaction, mass of products is

equal to mass of reactants: law of conservation of mass.

Physical property: quality of a substance that can be observed or measured without changing the substance’s composition. Ex. Length, color, temperatureExtensive: depend on amount of matter

present. Ex. Mass, length, volume

Intensive: do not depend on amount of matter present. Ex. Density, color, malleability (can be hammered), ductility (can be turned into wires), conductivity, melting point.

Chemical property : describes the behavior of a substance undergoing a chemical change. Describes how it reacts with other materials like air, water, and acids. Characteristics could be: acidity, flammability,

reactivity, oxidizing ability, explosiveness. Indicating it does not react is also a chemical

property.

Energy and changeEnergy is the capacity to do work. Always

involved when there is a change in matter.Endothermic and exothermic processes

Endothermic: energy is absorbed from the surroundings. (Ex. Boiling water)

YouTube - "Cool" Reaction: Ammonium Thiocyanate and Barium Hydroxide Octahydrate

Exothermic: energy is released to the surroundings. (Ex. fire)

YouTube - Exothermic reaction Potassium Permanganate

Learning check: 1. Classify the following as a chemical or physical

propertya. Is redb. Reacts with waterc. Boils at 88Cd. Dissolves in gasolinee. Is corrosive

2. Classify the following as a chemical or physical change

a. Alcohol evaporatingb. An explosionc. Digesting foodd. Salt dissolving in watere. Grass growing

Learning check: 1. Classify the following as a chemical or physical

propertya. Is red physicalb. Reacts with water chemicalc. Boils at 88C physicald. Dissolves in gasoline physicale. Is corrosive chemical

2. Classify the following as a chemical or physical change

a. Alcohol evaporating physicalb. An explosion chemicalc. Digesting food chemicald. Salt dissolving in water physicale. Grass growing chemical

Classwork: pg 62 #6-8

CHEMISTRY IUnit 1

The Science of Chemistry and Matter