Chapter 2 notesChapter 2 notes

KonichekKonichek

I.I. Chemistry-The study of matter and the Chemistry-The study of matter and the changes it undergoeschanges it undergoes

A.Pure substance or mixtureA.Pure substance or mixture-Matter with -Matter with a fixed composition and definite propertiesa fixed composition and definite properties

1. elements, and compounds1. elements, and compounds 2. separated using chemical 2. separated using chemical

processesprocesses

I. Chemistry-The study of matter and the changes it I. Chemistry-The study of matter and the changes it undergoesundergoes

A. matterA. matter- has mass and occupies space- has mass and occupies space 1. element- a substance which cannot be broken 1. element- a substance which cannot be broken

down any farther by ordinary chemical changes-115 down any farther by ordinary chemical changes-115 elements- could be more elements- could be more

a. Atom- This is the smallest piece of an elementa. Atom- This is the smallest piece of an element 1) 115 or so different types of atoms1) 115 or so different types of atoms 2. element designation2. element designation a. one or two letters which are the same world a. one or two letters which are the same world

widewide

B. compoundB. compound- two or more elements which are - two or more elements which are chemically combinedchemically combined

1. Have different physical properties than the 1. Have different physical properties than the elements which make them upelements which make them up

a. rust- iron(III) oxide, watera. rust- iron(III) oxide, water 2. Molecule- The smallest unit of a substance that 2. Molecule- The smallest unit of a substance that

exhibits all the properties characteristics of that exhibits all the properties characteristics of that substance( Book definition)substance( Book definition)

a. teacher definition- Two or more elements a. teacher definition- Two or more elements which are covalently bondedwhich are covalently bonded

b. Molecules act as a unit.b. Molecules act as a unit.

C. Chemical formulaC. Chemical formula-Tells the number of -Tells the number of elements and atoms in the compound, and elements and atoms in the compound, and the ratio which they combine.the ratio which they combine.

1. subscript- Tells the number of atoms 1. subscript- Tells the number of atoms in the compoundin the compound

2. coefficients- tells the number of 2. coefficients- tells the number of moleculesmolecules

HH22 + O + O22--22HH22O produces 2 O produces 2 molecules of watermolecules of water

– D.Formula mass- this is the sum of the D.Formula mass- this is the sum of the atomic mass of the elements in the atomic mass of the elements in the compoundcompound

E.To find the atomic mass have to look on E.To find the atomic mass have to look on the periodic table….Oxygen15.999--round it the periodic table….Oxygen15.999--round it off to 16.off to 16.

1.O1.O2= 2= 16 x2= 3216 x2= 32

2.H2.H22O= 2(1)+ 16= 18O= 2(1)+ 16= 18

3.Be(C3.Be(C22HH55OO2 2 ))

B. Mixture- Two or more substance which are put together which are B. Mixture- Two or more substance which are put together which are not chemically combinednot chemically combined

1. separated using physical means1. separated using physical means 2. Types of mixtures2. Types of mixtures a. heterogeneous-The parts are easily identifieda. heterogeneous-The parts are easily identified b. Homogeneous- The parts are not easily identified, looks b. Homogeneous- The parts are not easily identified, looks

the same throughoutthe same throughout c. Liquid mixturesc. Liquid mixtures 1. miscible- The parts of the mixture don’t separate, and it 1. miscible- The parts of the mixture don’t separate, and it

looks the same throughoutlooks the same throughout 2. immiscible- Two or more liquids which do not mix with 2. immiscible- Two or more liquids which do not mix with

each other.each other. d. mixing gases with liquids- gases can be dissolved in liquids d. mixing gases with liquids- gases can be dissolved in liquids

under pressure.under pressure.

III. MATTER AND ENERGY( 2.2)III. MATTER AND ENERGY( 2.2) A. Kinetic theoryA. Kinetic theory- An explanation of the behavior of - An explanation of the behavior of

mattermatter 1. All matter is made of atoms and molecules which act 1. All matter is made of atoms and molecules which act

as tiny particlesas tiny particles 2. the particles are in constant motion which depends 2. the particles are in constant motion which depends

upon the average Ke (temperature)of the substanceupon the average Ke (temperature)of the substance a. The particles are constantly colliding without a. The particles are constantly colliding without

losing energy( perfect elastic collisions)losing energy( perfect elastic collisions) 3. At the same temperature more massive particles 3. At the same temperature more massive particles

move slower and the less massive move fastermove slower and the less massive move faster B. KMT -B. KMT - helps understanding the differences in the 3 helps understanding the differences in the 3

common states of mattercommon states of matter

C, STATES OF MATTER- Depends on the C, STATES OF MATTER- Depends on the distance and the angles between molecules distance and the angles between molecules or atomsor atoms

1. gases- High energy content1. gases- High energy content a. no definite shape or volumea. no definite shape or volume b. Take the shape of the containerb. Take the shape of the container

2. Helium filled balloons lose air faster 2. Helium filled balloons lose air faster than air filled balloon- because the small He than air filled balloon- because the small He atom can go through the membrane of the atom can go through the membrane of the balloon easier.balloon easier.

3. pressure- the gases colliding with 3. pressure- the gases colliding with the sides of the container, as more atoms go the sides of the container, as more atoms go inside the balloon the more collisions inside the balloon the more collisions occur... eventually the balloon will burstoccur... eventually the balloon will burst

2. Liquids- Have a definite volume, but no 2. Liquids- Have a definite volume, but no definite shapedefinite shape

a. The atoms are able to move a. The atoms are able to move about each other freelyabout each other freely

1. fluids- all liquids and gases1. fluids- all liquids and gases b. Viscosity-A fluids ability to flowb. Viscosity-A fluids ability to flow 1. Depends upon an attraction 1. Depends upon an attraction

between particles in the liquidbetween particles in the liquid

3. Solids- Have definite shape and volume3. Solids- Have definite shape and volume a. The atoms are in a definite a. The atoms are in a definite

arrangement, this provides the shapearrangement, this provides the shape b. relatively low energy content.b. relatively low energy content. c. Strong attraction between c. Strong attraction between

atoms or moleculesatoms or molecules

D ENERGIES ROLED ENERGIES ROLE 1. MELTING- THE PROCESS OF 1. MELTING- THE PROCESS OF

CHANGING A SOLID TO A LIQUIDCHANGING A SOLID TO A LIQUID a. The particles are changing their a. The particles are changing their

positions and gaining energy, so they will positions and gaining energy, so they will not want to remain in their set positions.not want to remain in their set positions.

2. Evaporating- The particles have 2. Evaporating- The particles have gained enough energy to escape from the gained enough energy to escape from the liquid form to the gaseous formliquid form to the gaseous form

3. CONDENSATION- The process of changing 3. CONDENSATION- The process of changing from a gas to a liquid- losing heat.from a gas to a liquid- losing heat.

4. Sublimation- When a substance goes from a 4. Sublimation- When a substance goes from a solid directly into a gassolid directly into a gas

a, dry ice, iodinea, dry ice, iodine 5. During a change in state composition 5. During a change in state composition

remains constant and no mass is lostremains constant and no mass is lost E. Conservation of mass- Mass cannot be E. Conservation of mass- Mass cannot be

created or destroyed.created or destroyed. 1. Must end up with the same amount of matter 1. Must end up with the same amount of matter

which is started withwhich is started with

F. conservation of energyF. conservation of energy- Energy cannot - Energy cannot be created or destroyed- be created or destroyed- First Law of First Law of ThermaldynamicsThermaldynamics

a. The total amount of energy during a a. The total amount of energy during a chemical reaction remains constantchemical reaction remains constant

1. Burning of gasoline in a car 1. Burning of gasoline in a car engineengine

IV. PROPERTIES OF MATTERIV. PROPERTIES OF MATTER A. Chemical and physical propertiesA. Chemical and physical properties 1. Chemical property- the way a substance 1. Chemical property- the way a substance

reacts with other substances to form new reacts with other substances to form new substances with different physical properties.substances with different physical properties.

1. H1. H22 + + O O 22-----> ---> HH22OO 2. Reactivity- The ability of a substance 2. Reactivity- The ability of a substance

to combine chemically with other substances.to combine chemically with other substances. a. depends upon their position on a. depends upon their position on

the periodic table.the periodic table.

2. physical property-a characteristic of a substance which 2. physical property-a characteristic of a substance which can be observed or measured without changing the can be observed or measured without changing the composition of the substance.composition of the substance.

a, color, size, shape, state, density. melting a, color, size, shape, state, density. melting point, boiling point.point, boiling point.

b. density- mass per unit volume- characteristic b. density- mass per unit volume- characteristic propertyproperty

1. D= mass/ volume d=m/v1. D= mass/ volume d=m/v 2, buoyancy- The force with which more 2, buoyancy- The force with which more

dense fluid pushes a less dense substance upward.dense fluid pushes a less dense substance upward.

V. CHEMICAL AND PHYSICAL CHANGESV. CHEMICAL AND PHYSICAL CHANGES A. Chemical changes- A change that occurs A. Chemical changes- A change that occurs

when a substance changes composition by when a substance changes composition by forming one or more new substances.forming one or more new substances.

1. Have different physical properties1. Have different physical properties 2. electrolysis of water.2. electrolysis of water. 3. burning of gasoline- Changes the 3. burning of gasoline- Changes the

compositioncomposition B. physical changes- the composition doesn’t B. physical changes- the composition doesn’t

change.change.

Physical change- a change in statePhysical change- a change in state

Chemical change- rusting of a nailChemical change- rusting of a nail

1. The atoms which make up don’t change 1. The atoms which make up don’t change or are rearrangedor are rearranged

2. A change in size, shape, or state.2. A change in size, shape, or state. 3. Dissolving is a physical change- 3. Dissolving is a physical change-

sugar in watersugar in water

SUMMERIZINGSUMMERIZING

1.Definition Physical Change1.Definition Physical ChangeThe matter is the The matter is the same.same.2.The original matter can be recovered.The 2.The original matter can be recovered.The particles of the substance are rearranged.particles of the substance are rearranged.

3.Chemical Change3.Chemical ChangeThe matter is different. The matter is different. The old matter is no longer present. The old matter is no longer present.

4.The original matter cannot be recovered. 4.The original matter cannot be recovered. 5.The particles of the substance are broken apart, 5.The particles of the substance are broken apart,

and the atoms are rearranged into new particles, and the atoms are rearranged into new particles, forming a new substance.forming a new substance.