Chapter 3Matter and Energy

Matter Matter is defined as anything that occupies

space and has mass–things you can see, touch, taste, or smell.

States of Matter Matter can be

classified as solid, liquid, or gas based on what properties it exhibits.

States of Matter

State Particle Spacing Shape Volume Compress

Solid close fixed fixed no

Liquid close indefinite fixed no

Gas far apart indefinite indefinite yes

Composition of Matter Matter that is composed of only one kind of

atom or molecule is called a pure substance. Matter that is composed of different kinds of

atoms or molecules is called a mixture.

Pure SubstanceConstant Composition

MixtureVariable Composition

Matter

Composition of Matter Pure substance

Element—a substance that cannot be broken down into other substances by chemical methods.

Compound—a substance composed of a given combination of elements that can be broken down into those elements by chemical methods.

Composition of Matter Element: made of one

type of atom. Compound: made of

one type of molecule, or array of ions—more than one type of atom.

Composition of Matter Mixture

Mixtures that are uniform throughout are called homogeneous. Also known as solutions.

Mixtures that have regions with different characteristics are called heterogeneous.

Composition of Matter Homogeneous—appears to be

one substance, all portions of a sample have the same composition and properties.

Heterogeneous—presence of multiple substances can be seen, portions of a sample have different composition and properties.

Composition of Matter Mixtures can be separated

based on different physical properties of the components. Filtration

Composition of Matter Distillation

Composition of Matter

Composition of Matter Classify each of the following as a pure

substance (compound or element) or mixture (homogeneous or heterogeneous).1. Pure water2. Gasoline3. Jar of jelly beans4. Soil5. Copper metal

Physical and Chemical Properties The characteristics of a substance that

distinguish that substance are called its properties.

Physical and Chemical Properties Physical Properties are the characteristics of

matter that can be changed without changing its composition. Characteristics that are directly observable.

Physical and Chemical Properties Chemical Properties are the characteristics

that determine how the composition of matter changes as a result of contact with other matter or the influence of energy. Characteristics that describe the behavior of

matter.

Physical and Chemical Changes Changes that alter the state

or appearance of the matter without altering the composition are called physical changes.

Physical and Chemical Changes Changes that alter the

composition of the matter are called chemical changes.

Physical and Chemical Properties1. Classify each of the following as a physical or chemical property.

a. Ethyl alcohol boils at 78oCb. Sugar ferments to form ethyl alcoholc. Salt is stable at room temperature, it does not decomposed. 36 g of salt will dissolve in 100 g of water

2. Classify each of the following as a physical or chemical change.a. Sugar fermenting to form ethyl alcohol b. Dissolving of sugar in waterc. Iron metal meltingd. Iron combining with oxygen to form rust

Conservation of Mass Matter is neither created nor destroyed in a

chemical reaction.

Conservation of Mass 15 g elemental

magnesium is burned in the presence of oxygen; 25 g white magnesium oxide result. What mass oxygen was used up?

Energy Energy is anything that

has the capacity to do work.

All chemical and physical changes result in the matter changing energy.

Energy Potential energy is energy that is stored. Kinetic energy is energy of motion, or energy

that is being transferred from one object to another.

Energy Energy can neither be created nor destroyed.

Energy calorie (cal) is the amount of energy needed to raise

one gram of water by 1 °C.

Energy Conversion Factors1 calorie (cal) = 4.184 joules (J)

1 Calorie (Cal) = 1000 calories (cal)

1 kilowatt-hour (kWh) = 3.60 x 106 joules (J)

Energy and Chemical/Physical Change Exothermic process—when a chemical or

physical change results in the release of energy

Pote

ntia

l ene

rgy

Reactants

Products

Surroundings

reaction

Amount of energy released

Energy and Chemical/Physical Change Endothermic process—when a chemical or

physical change requires the absorption of energy

Surroundings

reaction

Pote

ntia

l ene

rgy

Products

Reactants

Amount of energy absorbed

Energy and Chemical/Physical Change Classify each process as exothermic or

endothermic1. Your hand gets cold when you touch ice.2. The ice gets warmer when you touch it.3. Water boils in a kettle being heated on a stove.4. Water vapor condenses on a cold pipe.5. Ice cream melts.

Temperature A measure of the random motions of the

components of a substance. Fahrenheit, Celsius, Kelvin

Heat: a flow of energy between two objects due to a temperature difference between the objects.

Temperature

Temperature Converting between scales

1. The normal body temperature for a dog is approximately 102oF. What is this equivalent to on the Kelvin temperature scale?

2. If the outside temperature is 298 K, what would you wear? What is this equivalent to on the Fahrenheit temperature scale?

K C C K

FC F C

+ 273 273

32 1.80 + 32

1.80

T T T T

TT T T

Heat Capacity Energy (Heat) Required to Change the

Temperature of a Substance Depends On: The amount of substance being heated (grams) The temperature change (degrees). The identity of the substance.

Heat Capacity Heat capacity is the amount of heat a

substance must absorb to raise its temperature by 1 °C.

Specific heat = heat capacity of 1 gram of the substance.

Heat Capacity Specific Heat

Capacities

Substance Specific Heat J/g°C

Aluminum 0.903 Carbon (dia) 0.508 Carbon (gra) 0.708

Copper 0.385 Gold 0.128 Iron 0.449 Lead 0.128 Silver 0.235

Ethanol 2.42 Water (l) 4.184 Water (s) 2.03 Water (g) 2.02

Summary of Topics: Chapter 3 Matter Pure substances: compounds and elements Mixtures: homogeneous and heterogeneous Chemical, Physical properties Chemical, Physical changes Energy, exothermic and endothermic Temperature conversions Heat Capacity (qualitative)