Cap 2 Ebbing Ingles

7/21/2019 Cap 2 Ebbing Ingles

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Chapter 2

Atoms,Molecules,

and Ions


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Chemical Substances: Formulas and Names

We explore how atoms combine in various ways to

yield the millions of known substances.

6. Chemical Formulas; Molecules and onic

!u"stances

#. $rganic Compounds%. &aming !imple compounds

Chemical Reactions: Equations

'. (riting Chemical )*uations

+,. -alancing Chemical )*uations


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2. The Structure of the Atom

a. Descrie Thomson!s e"periment in #hichhe discovered the electron.

. Descrie $utherford!s e"periment that ledto the nuclear model of the atom.


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3. Nuclear Structure; Isotopes

a. Nae and descri!e the nuclear particles

a"ing up the nucleus o# the ato.

!. $e#ine atomic number% mass number% and

nuclide.

c. &rite the nuclide sy!ol #or a givennucleus.

d. $e#ine and provide e'aples o# isotopes o#

an eleent.e. &rite the nuclide sy!ol o# an eleent.


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). Atoic *asses

a. $e#ine atomic mass unitand atomic mass.!. $escri!e ho+ a ass spectroeter can !e

used to deterine the #ractional a!undance

o# the isotopes o# an eleent.c. $eterine the atoic ass o# an eleent

#ro the isotopic asses and #ractional

a!undance.


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5. Periodic Table of the Eleents

a. !dentify periods and gro"ps on the periodic

table.b. #ind the ain$gro"p and transition

eleents on the periodic table.

c. Locate the al%ali etal and halogen gro"pson the periodic table.

d. &ecogni'e the portions of the periodic table

that contain the etals( nonetals( andetalloids )seietals*.


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Chemical Substances: Formulas and Names,. Cheical #or"las- olec"lar and !onic

/"bstances

a. 0eterine 1hen the cheical for"la of acopo"nd represents a olec"le.

b. 0eterine 1hether a cheical for"la is

also a olec"lar for"la.c. 0efine ion( cation( and anion.

d. Classify a copo"nd as ionic or olec"lar.

e. 0efine and provide eaples for the ter

formula unit.


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f. /pecify the charge on all s"bstances(1hether ionic and olec"lar.

g. rite an ionic for"la( given the ions.

6. 7rganic Copo"nds

a. List the attrib"tes of olec"lar s"bstances

that a%e the organic copo"nds.

b. Eplain 1hat a%es a olec"le a

hydrocarbon.

c. &ecogni'e soe f"nctional gro"ps of

organic olec"les.


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8. aing /iple Copo"nds

a. &ecogni'e ionic copo"nds.

b. Learn the r"les for predicting the charges ofonatoic ions in ionic copo"nds.

c. Apply the r"les for naing onatoic ions.

d. Learn the naes and charges of coonpolyatoic ions.

e. ae an ionic copo"nd fro its for"la.

f. rite the for"la of binary copo"nd froits nae.


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g. Determine the order of elements in a binary(molecular compound.

h. Learn the rules for naming binary molecular

compounds.i. !ame a binary compound from its formula.

". #rite the formula of a binary compound

from its name.

$. !ame a binary molecular compound from

its molecular model.

l. %ecogni&e molecular compounds that are

acids.


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m. Determine hether an acid is an o)oacid.

n. Learn the approach for naming binary acids

and o)oacids.

o. #rite the name and formula of an anion

from the acid.

p. %ecogni&e compounds that are hydrates.*. Learn the rules for naming hydrates.

r. !ame a hydrate from its formula.

s. #rite the formula of a hydrate from itsname.


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Chemical Reactions: Euations

,. #riting Chemical -*uationsa. dentify reactants and products in a

chemical e*uation.

b. #rite chemical e*uations using appropriatephase labels/ symbols of reaction

conditions/ and the presence of a catalyst.


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1. alancing Chemical -*uationsa. Determine if a chemical reaction is

balanced.

b. 3aster the techni*ue for balancingchemical e*uations.


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Postulates of Daltons Atomic Theory

All matter is composed of indivisible atoms. Anatom is an e)tremely small particle of matter thatretains its identity during chemical reactions.

An element is a type of matter composed of onlyone $ind of atom.


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Atomic Symbol

A one- or two-letter notation used to represent an

atom corresponding to a particular element.

The irst letter must !e "##$%CA&$.

The second letter' when present' must !e

lowercase.

&ym!ols come rom the element name(

several names come rom Latin.


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Law of Multiple Proportions

*hen two elements orm more than one

compound' the masses o one element in thesecompounds or a i+ed mass o the other element

are in small' whole-num!er ratios.


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Like Dalton, todays chemists model

atoms using spheres. odern models

are o!ten dra"n using computer

programs and use di!!erent colors to

represent atoms o! di!!erent elements.#hich o! these models depicts C$2%

A & C D '

' is C$2


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Structure of the Atom

The atom is composed of two parts:Nucleus

Central core

Positively charged

Contains most of the atoms mass

Electrons

ery light

!egatively charged

"#ist in the region aro$nd the n$cle$s


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Discovery of the Electron

J. J. Thomson used an apparatus similar to the

one shown on the next slide, a athode ray tu!e.

"e disovered that the partiles that ma#e up the

athode ray are negative and are part o$ all matter.This $inding is illustrated on the $ollowing slides.

As a result, Thomson onluded that atoms are

not indivisi!le, as %alton had postulated.


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Cathode 'ay Tu!e


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Cathode rays are attrated to

the positive end o$ themagnet and repelled !y the

negative end.


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Thomsons experiments allowed him to calculate

the ratio o the electrons mass to its charge.

!o"ert #illi$an calculated the charge on the

electron. %e determined the charge on variousdrops o oil and ound the smallest increment in

charge&that is' the charge on the electron. This is

illustrated on the next slide.


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Nuclear Model of the Atom

Experiments done in Ernest Rutherfords

laoratory used positively !harged alpha parti!les

to omard very thin gold "and other metals# foil.

$ost alpha parti!les passed through the foil% ut a

fe& &ere s!attered at large angles% sometimesalmost straight a!'&ard.

(ased on these findings% Rutherford proposed that)).)*+ of the atoms mass is in the positively

!harged nu!leus.


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Proton

A nu!lear parti!le having a positive !harge e/ual

to that of the ele!tron and a mass more than 8--

times that of the ele!tron.

0he numer of protons in an atom is !alled the

atomic number, Z.

An element is a sustan!e &hose atoms have thesame numer of protons and thus the same atomi!

numer% Z.


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Neutron

A nu!lear parti!le having a mass almost e/ual to

that of the proton ut no ele!tri!al !harge

0he mass number,A, is the total numer of

protons and neutrons in the nu!leus.

soto!es are atoms &hose nu!lei have the same

atomi! numer "numer of protons# ut different

numers of neutrons "mass numer#.


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Nuclide

An atom characterized by a certain atomicnumber, Z, and mass number,A.

Nuclide symbol

!amples" Li#3 C$3

%

symbolChemicalA&

Na23$$


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Write the nuclide symbol for the

atom that has ! protons and 2"

neutrons.

K3919

Atomic number# Z$ !

%he element is potassium& '.

(ass number#A $ ! ) 2" $ 3!

%he nuclide symbol is


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Atomic Mass

%he average atomic mass for the naturally

occurring element e+pressed in atomic mass units,amu-.

Atomic Mass Unit

/ual to e+actly one0t1elfth the mass of a carbon0

2 atom


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An element has four naturally occurring

isotopes. %he mass and percentage of

each isotope are as follo1s#

Percentage Abundance Mass (amu)

.4 2"3.!3

23. 2"*.!4*22. 2".!*!

*2.3 2".!

What is the atomic 1eight and name of

the element5


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%o find the portion of the atomic 1eight due to

each isotope& multiply the fraction by the mass ofthe isotope. %he atomic 1eight is the sum of these

products.

FractionalAbundance

Mass (amu) Mass FromIsotope

"."4 2"3.!3 3."""4"

".23 2"*.!4* 4."!!2"".22 2".!*! 4.**34".*23 2".! ".

22"."!

%he atomic 1eight is 2" amu6 the element is lead.


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Periodic Table of the Elements

A tabular arrangement of elements in ro1s and

columns& highlighting the regular repetition ofproperties of the elements.


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A period consists of the elements in onehorizontal row.

A group consists of the elements in one vertical

column.

roups are num!ered using two systems"

#$%AC &um!ers ' through '(

)lder system *oman numerals #+,### andthe letters A and -


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Metal

A su!stance or mi0ture that has a characteristicluster or shine and is generally a good conductorof heat and electricity.

Nonmetal

An element that does not e0hi!it thecharacteristics of a metal

Metalloid

An element having characteristics of !oth metalsand nonmetals


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Molecule

A definite group of atoms that are chemically!onded together 1tightly connected !y attractive

forces.

Molecular Formula

A formula giving the e0act num!er of differentatoms of an element in a molecule.


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PolymerA very large molecule that is made up of a num!er

of smaller molecules repeatedly lined together.

Monomers

4he small molecules that are lined together to

form a polymer.


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An ion is an electrically charged particle o!tained from anatom or chemically !onded group of atoms !y adding orremoving one or more electrons.

A cation is a positively charged ion formed !y losing one ormore electrons. A cation is named !y its element namefollowed !y the word ion. 5or e0ample6 &a7 is the sodiumion6 etc. $nder the definition of anion add the following" Ananion is named !y changing the last part of the elementname to +ide followed !y the word ion. 5or e0ample6 58 isthe fluoride ion6 )28 is the o0ide ion6 &38 is the nitride ion6etc.

An anion is a negatively charged ion formed !y gainingone or more electrons.


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An ionic compound is composed of cations and

anions.

Ions are arranged in a repeating three-dimensional

pattern, forming a crystal.

he formula of an ionic compo!nd gives the

smallest possi"le integer n!m"er of ions in thes!"stance #$itho!t $riting charges% so that thecom"ination is electrically ne!tral.

he form!la gives the formula unit of thecompo!nds. A form!la !nit is not a molec!le&


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(hat is form!la of the ioniccompo!nd of )g2* and +-

he common m!ltiple of the charges is ', so $e

need three )g2* and t$o +-. he res!lting form!la

is)g+2


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(hat is the form!la of the ionic

compo!nd of Ca2* and /04-

he common m!ltiple of the charges is ', so $e

need three Ca2* and t$o /04-. he res!lting

form!la isCa#/04%2


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Organic Compounds

An important class of molec!lar s!"stances they

contain car"on com"ined $ith other elements 3

nota"ly hydrogen, oygen, and nitrogen.

Hydrocarbons contain only car"on and hydrogen.


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A f!nctional gro!p is a reactive portion of amolec!le that !ndergoes predicta"le reactions.

ExamplesName ofGroup

FunctionalGroup

)ethyl alcoholAlcohol6imethyl ether7ther

Acetic acidCar"oylicacid


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Naming Inorganic Compounds

9. he cation is al$ays named first $ith the

name of the cation $itho!t the $ord ion.

2. he anion is named second $ith the name

of the anion $itho!t the $ord ion.

. 7amples:

Cation Anion Name

+a* ;r-


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Monatomic ions

Ions formed from a single atom.

Common monatomic ions are listed on the net

slide "y gro!p and "y period.

Common )onatomic Ions of the


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Common )onatomic Ions of the

)ain-=ro!p 7lements

;i*/"2*l*,

l*;a2*Cs*

I-

e2-


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Rules for Predicting the Charge on a

Monatomic Ion

9. )ost main-group metals have one monatomic

ions $ith a charge eB!al to the gro!p n!m"er.

Al, in =ro!p IIIA#%, has one ion, Al*.


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2.


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. )ost transition metals form more than one

cation, of $hich one is *2.Dn and Cd form only the *2 ion.

Ag forms only the *9 ion.

4. Nonmetal main-group elements form one

monatomic anion $ith a charge eB!al to the

gro!p n!m"er min!s 1.

@ in =ro!p IIA#9% forms the @- ion.

< in =ro!p IA#9'% forms the


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Naming Monatomic Ions

)onatomic cations are named after the element if

the element forms only one cation.


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If more than one cation forms:

a. In the oman n!meral and is enclosed inparentheses.

C!2* is copper#II%.C!* is copper#I%.

". In an older system, the s!ffic 3ic#for thehigher-charged cation% or 3ous for thelo$er-charged cation% is added to the

elementFs stem.C!2* is c!pric.

C!* is c!pro!s.


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@e* is iron#III% or ferric ion.

@e2* is iron#II% or ferro!s ion.

g2* is merc!ry#II% or merc!ric ion.

he second ion merc!ry forms is diatomic:

g22* is merc!ry#I% or merc!ro!s ion.


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Cr* is chromi!m#III% or chromic ion.

Cr2* is chromi!m#II% or chromo!s ion.

)n2*

is manganese#II% or mangano!s ion.Co2* is co"alt#II% or co"alto!s ion.

Dinc forms only Dn2*, so it is called Ginc ion.Cadmi!m forms only Cd2*, so it is called cadmi!m

ion.


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Polyatomic Ion

An ion consisting of t$o or more atoms chemically

"onded together and carrying an electrical charge.

a"le 2.5 lists common polyatomic ions.

Cations


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Cations

merc!ry#I% or merc!ro!s g22*

ammoni!m +4

*

Anions

peroide 02-

hydroide 0-

cyanide C+-


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phosphate /04

-

monohydrogen phosphate /042-

dihydrogen phosphate 2/04-

car"onate C02-

hydrogen car"onate #"icar"onate% C0-

s!lfate


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acetate C202-

oalate C2042-

chromate Cr042-

dichromate Cr 202-

permanganate )n04-

nitrate +0-

nitrite +02-


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hypochlorite Cl0-

chlorite Cl02-

chlorate Cl0-

perchlorate Cl04-

(hat are the names of the follo$ing


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(hat are the names of the follo$ing

ionic compo!nds

;a0

Cr2#


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(hat are the chemical form!las for

the follo$ing ionic compo!nds

potassi!m car"onate

manganese#II% s!lfate

he ions ?* and C02- form ?2C0

he ions )n2* and


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Binary Molecular Compounds

A compo!nd composed of only t$o elements.

;inary compo!nd of a metal and a nonmetal are

generally named !sing ionic r!les.


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Naming Binary Molecular Compounds

(e !s!ally name the elements in the order givenin the form!la.

+ame the first element !sing the element name.

+ame the second element !sing the element root

* -ide s!ffi.


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Add a prefix to each name to indicate the numberof atoms of that element. he prefix mono is used

only !hen needed to distinguish t!o compounds

of the same t!o elements.

he final vo!el of the prefix is often dropped !hen

follo!ed by an element name that begins !ith avo!el. "xygen is the most common example.

#2"$ dinitrogen tetroxide %&a' is dropped(

#" nitrogen monoxide %only one &o'(%also called nitric oxide(

Prefixes (Greek)


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( )

"ne %)( mono*

!o %2( di*

hree %+( tri*

,our %$( tetra*

,ive %-( penta*

ix %/( hexa*even %7( hepta*

ight %1( octa*

#ine %( nona*

en %)0( deca*


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ome compounds have common names that differ

from their systematic names3

42 hydrogen sulfide %the &di' is omitted(

42" !ater

#4+ ammonia

Common names need to be memori5ed.

Acids and Corresponding Anions


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"xoacids contain hydrogen6 oxygen6 and a thirdcentral atom.

o name an acid from its anion name3

). Change an ate suffix to ic.

2. Change an ite suffix to ous.+. Add the !ord &acid.''

,or example34#"+ nitric acid

42"$ sulfuric acid

"xoacid"xoanion


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sulfuric

acid

42"$sulfate ion"$2*

sulfurous

acid

42"+sulfite ion"+2*

phosphoricacid4+8"$phosphate ion8"$

+*

nitric acid4#"+nitrate ion#"+*

nitrous

acid

4#"2nitrite ion#"2*

carbonic

acid

42C"+carbonate

ion

C"+2*


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hypochlorous

acid

4Cl"hypochlorite

ion

Cl"*

chlorous

acid

4Cl"2chlorite

ion

Cl"2*

chloricacid

4Cl"+chlorateion

Cl"+*

perchloric

acid

4Cl"$perchlorate

ion

Cl"$*

"xoacid"xoanion

9hat are the names of the


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follo!ing compounds:

",2

$#$;Cl+

",2 is oxygen difluoride

$#$ is tetrasulfur tetranitride

;Cl+ is boron trichloride

9hat are the formulas for the


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follo!ing binary molecularcompounds:

carbon disulfidenitrogen tribromide

dinitrogen tetrafluoride

he formula for carbon disulfide is C2.

he formula for dinitrogen tetrafluoride is #2,$.he formula for nitrogen tribromide is #;r+.

;romine has an oxoacid6 4;r"26


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bromous acid %compare to 4Cl"26chlorous acid(. 9hat are the name

and formula of the corresponding

anion:

he anion corresponding to 4;r"2 is

bromite6 ;r"2*.


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Hydrate

A compound that contains !ater molecules !ea


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4ydrates are named using the anhydrous %!ithout

!ater( compound name follo!ed by the prefix for

the number of !ater molecules included and the!ord &hydrate.'

,or example3Cu"$-42" is named

copper%==( sulfate pentahydrate.

A compound !hose common name


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is green vitriol has the chemicalformula ,e"$742". 9hat is the

chemical name of this compound:

,e"$742" is iron%==( sulfate heptahydrate.

Calcium chloride hexahydrate is


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used to melt sno! on roads. 9hatis the chemical formula of the

compound:

he chemical formula for calcium chloride

hexahydrate is CaCl2/42".

A chemical equation is the symbolic


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representation of a chemical reaction in terms ofchemical formulas.

,or example3 2#a > Cl2 2#aCl

Reactants are the starting materials? they are!ritten on the left of the e@uation.

Products are the materials at the end of thereaction? they are !ritten on the right of the

e@uation.


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;ecause a reaction must accurately describe thechemical reaction6 it must be consistent !ith the

la! of conservation of mass.

9hen this is not the case6 after correct formulas

are !ritten for each reactant and product6 the

coefficients are adusted so that the same numberof each atom is present in both the reactants and

the products.

his is called balancing the equation.


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,or example6 the reaction of sodium !ith chlorine

produced sodium chloride.

,irst6 !e determine the correct formula for each

compound.

odium is #a.

Chlorine is Cl2.

odium chloride is #aCl.

econd6 !e !rite the reaction.


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#a > Cl2 #aCl

hird6 !e chec< the number of each atom on each

side of the e@uation.

his e@uation sho!s t!o Cl atoms on the reactant

side and only one Cl atom on the product side. o

balance the Cl atoms6 !e insert a coefficient of &2'

before #aCl on the product side.

#a > Cl2 2#aCl

# Cl2 2# Cl


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#a > Cl2 2#aCl

#o! the #a are not balanced3 there is one on the

reactant side and there are t!o on the productside. o balance #a6 !e insert the coefficient &2'

before #a on the reactant side.

2#a > Cl2 2#aCl

he reaction is no! balancedB

;alance the follo!ing e@uation3


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C2 > "2 C"2 > "2

ally the number of each atom on each side3

C ) on reactant side? ) on product side

2 on reactant side? ) on product side" 2 on reactant side? $ on product side

;egin by inserting the coefficient &2' before

"2 on the product side. 9e leave "2 until

later because it is an element.

C " C" 2"


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C2 > "2 C"2 > 2"2

ally the atoms again3C ) on reactant side? ) on product side

2 on reactant side? 2 on product side

" 2 on reactant side? / on product side

=nsert a &+' before "23

C2 > +"2 C"2 > 2"2


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#4+ > "2 #" > 42"


# ) on reactant side? ) on product side

4 + on reactant side? 2 on product side" 2 on reactant side? 2 on product side

;egin by inserting the coefficient &2' before

#4+ on the reactant side and the coefficient &+'before 42" on the product side. 9e leave "2until later because it is an element.

2#4 > " #" > +4 "


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2#4+ > "2 #" > +42"

ally the atoms again3

# 2 on reactant side? ) on product side

4 / on reactant side? / on product side

" 2 on reactant side? $ on product side

o balance #6 insert a &2' before #"3

2#4+ > "2 2#" > +42"

2#4+ > "2 2#" > +42"


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2#4+ > "2 2#" > +42"

ally the atoms again3

# 2 on reactant side? 2 on product side


" 2 on reactant side? - on product side

ince this gives us an odd number oxygens6 !e

double the coefficients on #4+6 #"6 and 42"and to balance "6 insert a &-' before "2.

ally the atoms again to double chec


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ally the atoms again to double chec -"2 $#" > /4

2"

# $ on reactant side? $ on product side

4 )2 on reactant side? )2 on product side" )0 on reactant side? )0 on product side




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C24-"4 > "2 C"2 > 42"


C 2 on reactant side? ) on product side

4 / on reactant side? 2 on product side" + on reactant side? + on product side

;egin by balancing 4. =nsert the coefficient &+'

before 42" on the product side. 9e leave "2until later because it is an element.


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C24-"4 > "2 C"2 > +42"


C 2 on reactant side? ) on product side

4 / on reactant side? / on product side" + on reactant side? - on product side

o balance C6 insert a &2' before C"2.


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C24-"4 > "2 2C"2 > +42"


C 2 on reactant side? 2 on product side

4 / on reactant side? / on product side" + on reactant side? 7 on product side

o balance "6 insert a &+' before "2.


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C24-"4 > +"2 2C"2 > +42"

ally the number of each atom on each side3C 2 on reactant side? 2 on product side


" 7 on reactant side? 7 on product side


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