Chapter 5: The Structure of Matter



Chapter 5: The Structure of Matter

Compounds vs. Mixtures

_______________

- different substances placed together

- not _____________combined

- can be separated by physical means

- each substance keeps its own _____________

- can have any amount of each substance

________________

- combine in definite _____________

- when combined, new substance has its own properties

- chemically combined

- held together by chemical bonds

- ______________- the attractive force that holds atoms or

ions together

- chemical _______- shows the types and number of atoms

or ions making up the simplest unit of

the compound

- always the same for a compound

- definite ratio

- Ex.- water is always H2O

- state, location, or amount doesn’t

matter

- H2O2 - hydrogen peroxide

- both H2O and H2O2 have H and

O, but they are very different

- chemical _____________- the arrangement of atoms in a

substance

- how atoms are arranged determines

many of a compound’s properties

- 2 important descriptions

1) bond _______- distance between the nuclei of two

bonded atoms

2) bond ______- how the atoms are oriented in space

- applies only when there are three or

more atoms

[pic]

- ball and _________ model- shows bonding and angles

- “ball” represents atoms

- “stick” represents bonds

- ___________ formula- good for showing structures

- symbol and lines replace ball and stick

- Ex.- O

H H

- ________ filling model- shows relationship in how much

space is taken up by each atom

- doesn’t show bond ________ and

___________

[pic]

***different structures give different properties***

- Ex.- SiO2 quartz and sand

- forms large network structure

- Si-O-Si

- all bond angles are 109.50

- bond angle continues throughout structure

- _______________

- makes it very hard, rigid structure

- takes lots of ___________ to break bonds

- causes ________ in melting and boiling points

[pic]

- Ex.- NaCl

- crystalline

- repeating ____________ of strong bonds

- Na+ ions and Cl- ions

- strong attraction = strong bond

- results in high melting and boiling points

- Ex.- sugar (C12H24O12)

- C, H, and O bond together to make a molecule

- strong bonds

- attraction _____________ molecules is weak

- N2, O2, and CO2

- colorless, odorless, strongly bonded molecules

- almost no attraction between molecules

- allows them to ________ _______

- why gases take up a lot of space

- compounds made of ______________have very different

properties

[pic]

- even though H2O and H2S are similar in structure, the

boiling point and melting point are different

- water’s molecules are more ________ to each other

than dihydrogen sulfide’s are

- hydrogen bonds between molecules

- weak bond due to slightly positive and slightly

negative portion of water molecule (________)

- makes water a ___________at room temperature

BONDING

- ____________- energy that holds atoms together

- type of bond affects ____________

- result of valence electrons interacting

- interact until outer energy level is ________

- resemble __________ gas

- sometimes represented by sticks

- _____________ would be more accurate

- nuclei move in all directions

- bond distances are averages of those

movements

3 types of bonds

1) ______________ Bonding

- result of oppositely charged atoms attracting

- one atom (non-metal) rips electrons away from another

atom (metal)

- metal ions are “____” charged

- _______ electrons

- non-metal ions are “______“ charged

- ________ electrons

- both are stable as a result of electron movement

- oppositely charged ions attract to form an ionic

compound

- Ex.- NaCl (table salt)

Na+ + Cl-

- sodium ion _________ several chlorine ions

- build up of chlorine ions attracts several more

sodium ions

- sets up a ____________ of bonded ions

- lots of Na+ and Cl- are bonded together

- ratio is 1:1 NaCl

- Ex.- Ca2+ + F-

CaF2

- as crystals, charges are locked into place

- very high melting points

- _________________ in water or melted

- will ____________ electricity

- electricity is e- moving from one place to another

- when ________ or _______; ions are now free to

move and pass energy through the substance

2) ____________ Bonds

- bonds formed by the attraction between positively

charged _______ ions and the electrons around them

- results in closely ________ atoms

- overlapping orbitals

- e- are free to move as they please

1) allows metals to conduct electricity

2) makes them ___________

- atoms slide past each other without breaking any

bonds

3) _________________ Bonds

- bond formed when atoms share one or more pairs of

electrons

- formed between non-metal atoms

- solids, liquids, or gases

- most have ______melting points

- except compounds with network structures

- crystalline

- molecules are free to move when dissolved or melted

- stay intact; do not conduct electricity

- not charged

2 types

1) _______________ covalent bonds

- bonds which share electrons equally

- Ex.- Cl2

- Chlorine has 7 valence electrons

[pic]

- shared electrons are attracted to “___”

charged nucleus of other atom

- equal “+” charge; equal sharing

- line between carbon atoms represents one

___ of electrons being shared (single bond)

[pic]

- Ex.- O2 ___________ bond

[pic]

- 2 pairs of electrons shared

- Ex.- N2 ___________ bond

[pic]

- 3 pairs of electrons shared

- Ex.- C2 ____________ bond

[pic]

- 4 pairs of electrons shared

- most possible

- more bonds = stronger bonds

- requires more energy to break them

2) ____________ covalent bonds

- shared electrons are not shared ____________

- usually electrons are attracted to atoms of

elements that are located further to the ____and

closer to the _______ of the periodic table

________________ Ions

- an ion made of two or more atoms

- have covalently bonded atoms and have lost or gained

electrons

[pic]

- all are negatively charged except ammonium; NH4+

Monatomic Ions vs. Polyatomic Ions

Monatomic Ions Polyatomic Ions

sodium oxide Na2O sodium sulfate Na2SO4

iron (III) fluoride FeF3 potassium carbonate K2CO3

barium iodide BaI2 calcium chlorate Ca(ClO3)2

copper (II) oxide CuO tin (II) acetate Sn(CH3COO)2

- to I.D. a polyatomic ion:

1) see if ____ is at the beginning of the compound

2) cover up _________ element with finger

3) is there more than one element left

- if yes, it is polyatomic

- if no, it is monatomic

- many contain oxygen

- end in –ite or –ate

- ate used for ion with _______ oxygen

- ite used for ion with _______ oxygen

- Ex.- sulfate SO4 2-

sulfite SO3 2-

nitrate NO3 1-

nitrite NO2 1-

chlorate ClO3 1-

chlorite ClO2 1-

Compound Names and Formulas

- names reflect the elements from which the compounds are

found

Ionic Compounds

- formed from attraction between ______ (+) and _____ (-)

- _________ is written first; followed by ___________

- cation is unchanged

- anion ending is altered

- usually ends in –ide

- Ex.- fluorine; fluoride

- oxygen; oxide

- Ex.- NaCl table salt

- Sodium Chloride

- _____________ metals

- may form more than one cation

- charge follows cation in compound

- in _____________ numerals

- Ex.- FeO vs. Fe2O3

- black powder - reddish brown

- melts at 14200 C - rust

- melts at 15650 C

- iron (II) oxide - iron (III) oxide

- total charge on compound is __________

- “+” equal to “-“

Fe2O3

- each oxygen is a -2 charge; 3 molecules

(-2)(3)= -6

- total positives must equal +6

2 Fe atoms = +6

+6/2 = +3 each

Ionic Compound Formulas

1) find charge of each _________

2) write symbol for ____________ first

3) find ________ common multiple of ions’ charges

4) write chemical formula

- _________ indicate how many of each ion are needed

to be neutral

- Ex.- Aluminum and Fluoride

1) Al = +3 F = -1

2) Al3+F-

3) least common multiple = 3

4) AlF3 or AlFFF

+3;-1;-1;-1

+3;-3

0; neutral

Polyatomic Ion Formulas

- to determine the charge of a polyatomic ion (2 ways)

1) memorize, memorize, memorize

2) check the ________of the positive part (left side) of

compound

- polyatomic part (________ side) must be equal and

opposite

- Ex.- NaOH

Na = +1 so OH must = -1

- Ex.- Na2CO3

Na = +1, there are two atoms Na; = +2

CO3 = -2

- Ex.- Ca(ClO3)2

Ca = +2; right side must equal -2

- there are two ClO3 molecules

- each is a -1 charge

-1 + -1 = -2

Naming Covalent Compounds

- use numerical _________ to tell how many atoms of each

element

- which ever element is further to the _____ on the periodic

table is named second and ends in –____________

- Ex.- 1 boron and 3 fluorine atoms atoms…BF3

- boron trifluoride

- Ex.- N2O4

- dinitrogen tetroxide

[pic]

- ___________formula- the composition of a compound in

terms of the relative numbers and

kinds of atoms in the simplest ratio

- Ex.- 142 g sample of unknown substance

- found to contain only phosphorus and oxygen

62 g P and 80 g O

62 g P x 1 mol P 80 g O x 1 mol O

30.97 g P 16 g O

2 mol P : 5 mol O

P2O5

- Ex.- CH2O

- empirical formula for formaldehyde, acetic acid,

and glucose

- all are very different

- must use molecular formula to tell the

difference

- ___________formula- a chemical formula that shows the

number and kind of atoms in a

molecule, but not the arrangement of

atoms

- sometimes empirical and molecular formulas are the ____

- Ex.- water; both are H2O

| |empirical formula |molecular formula |

|formaldehyde |CH2O |CH2O |

|acetic acid |CH2O |C2H4O2 |

|glucose |CH2O |C6H12O6 |

- __________compound- covalently bonded compound that

contains carbon

- usually contains hydrogen

- may also contain other atoms

- ______________- compound made entirely of carbon and

hydrogen

- carbon has ___ valence electrons for bonding

- maximum number of bonds possible (4)

Alkanes, Alkenes, Alkynes

Alkanes

- hydrocarbons with only ___________ bonds

- _______________- n-alkanes

- when alkanes’ carbons line up in a

straight row

- if 3 or less; always normal

- more than 3; may have branches, rings

| | | | |condensed structural | |

|prefix |# of carbons |name |molecular |formula |structural formula |

| | | |formula | | |

|meth |1 |methane |CH4 |CH4 |c |

|eth |2 |ethane |C2H6 |CH3CH3 |c-c |

|prop |3 |propane |C3H8 |CH3CH2CH3 |c-c-c |

|but |4 |butane |C4H10 |CH3(CH2)2CH3 |c-c-c-c |

|pent |5 |pentane |C5H12 |CH3(CH2)3CH3 |c-c-c-c-c |

|hex |6 |hexane |C6H14 |CH3(CH2)4CH3 |c-c-c-c-c-c |

|hept |7 |heptane |C7H16 |CH3(CH2)5CH3 |c-c-c-c-c-c-c |

|oct |8 |octane |C8H18 |CH3(CH2)6CH3 |c-c-c-c-c-c-c-c |

|non |9 |nonane |C9H20 |CH3(CH2)7CH3 |c-c-c-c-c-c-c-c-c- |

|dec |10 |decane |C10H22 |CH3(CH2)8CH3 |c-c-c-c-c-c-c-c-c-c |

[pic]

Alkenes

- hydrocarbons with at least 1 _________ bond (C=C)

- ending is –ene

- smallest is ethane

- must have 2 carbons for double bond

- general formula C___H____

Alkynes

- hydrocarbons with at least 1 ________ bond (C=C)

- ends in –yne

- smallest is ethyne

- general formula C____H______

- alcohol (-____ group)

- OH is called a hydroxyl group

- Ex.- methanol (CH3OH)

- ethanol (CH3CH2OH)

- isopropanol (C3H8O or (CH3)2CHOH)

Polymers

- _________- a large molecule that is formed by more than

five monomers or small units

- Ex.- polyethylene

- poly- many

-ethene- alkene (C2H4)

- C2H4 is the monomer

- some occur _________________

- Ex.- rubber, wood, cotton, wool, starch, protein, DNA

- some are man made

- usually plastics or fibers

- properties are determined by structure

- polymer _____________

- polymer molecules are like a bowl of spaghetti

- chains get tangled, but can slide past each other

- doesn’t keep shape (no memory)

- Ex.- milk jug

- some polymers will _________ _________

- creates “memory”

- returns to its original shape

- Ex.- rubber band

Biochemical Compounds

several important ones, we’ll look at 4

1) ____________________

- energy for living things

- Ex.- glucose

- glucose is used; unused glucose is stored

- in animals- glycogen

- in plants- starch

2) _______________

- storage for energy (extra glucose)

- liquid; __________

- solid; __________

3) __________________

- uses

- structural components in cells

- hair

- muscles

- hemoglobin

- made of ____________ __________

- 20 amino acids

C

- 20 A.A. are responsible for all proteins we know of

- all but 8 our body can make

- 8 _____________ A.A. must come from our diet

- eggs, dairy products, organ meats

4) _________ _________

- Ex.- deoxyribonucleic acid (DNA)

- ribonucleic acid (RNA)

- determines genetic make up

DNA

- paired chain or strands

- shape…__________ _________

- like a twisted ladder

RNA

- 1 strand

- shape…straight

- DNA and RNA are made of alternating sugar and phosphate molecules connected to 1 of 4 bases (monomers)

1) __________

2) __________

3) __________

4) __________

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