Chapter 3 Powerpoint Le

8/9/2019 Chapter 3 Powerpoint Le

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Chapter 3

Structure and Properties of

Ionic and CovalentCompounds

Denniston

Topping

Caret

5th Edition

Copyright The McGraw-Hill Companies, Inc. Permission required or reproduction or display.


2/87

3.1 Chemical Bonding

• Chemical bond - the force of attraction

between any two atoms in a compound

• This attractive force overcomes the

repulsion of the positively charged nuclei of

the two atoms participating in the bond

• Interactions involving valence electrons are

responsible for the chemical bond


3/87

3 . 1 C

h e m i c a

l B o n d i n g ewis !ymbols

• ewis symbol "ewis structure# - a way torepresent atoms using the element symboland valence electrons as dots

• $s only valence electrons participate in bonding% this ma&es it much easier to wor&with the octet rule

• The number of dots used correspondsdirectly to the number of valence electronslocated in the outermost shell of the atoms

of the element


4/87

3 . 1 C

h e m i c a

l B o n d i n g ewis !ymbols

• 'ach (side) of the symbol represents an atomicorbital% which may hold up to two electrons

• *sing ewis symbols

+ ,lace one dot on each side until there are four dots around

the symbol

+ ow add a second dot to each side in turn

+ The number of valence electrons limits the number ofdots placed

+ 'ach unpaired dot "unpaired electron of the valence shell#is available to form a chemical bond


5/87

ewis ot !ymbols for

/epresentative 'lements

3 . 1 C

h e m i c a

l B o n d i n g


6/87

3 . 1 C

h e m i c a

l B o n d i n g

,rincipal Types of Chemical Bonds0

Ionic and Covalent

• Ionic bond - a transfer of one or moreelectrons from one atom to another

• orms attractions due to the opposite charges of

the atoms

• Covalent bond - attractive force due to thesharing of electrons between atoms

• !ome bonds have characteristics of bothtypes and not easily identified as one or theother


7/87

Ionic Bonding

• /epresentative elements form ions thatobey the octet rule

• Ions of opposite charge attract each other

creating the ionic bond• 2hen electrons are lost by a metal and

electrons are gained by a nonmetal

+ 'ach atom achieves a (oble as)configuration

+ 4 ions are formed5 a cation and anion% whichare attracted to each other

3 . 1 C

h e m i c a

l B o n d i n g


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3 . 1 C

h e m i c a

l B o n d i n g

Consider the formation of

aCl

a 6 Cl aCl

!odium has a low

ioni7ation energy it

readily loses this

electron a a6 6 e-

2hen sodium loses the

electron% it gains the

e configuration

Chlorine has a high

electron affinity

2hen chlorine gainsan electron% it gains

the $r configuration

−

−

!"#$%&'+( 0..

..Cl0e

..

..Cl0

Ionic Bonding


9/87

3 . 1 C h

e m i c a l

B o n d i n g

'ssential eatures of Ionic Bonding

• $toms with low I.'. and low '.$. tend to form positive ions

• $toms with high I.'. and high '.$. tend to form

negative ions

• Ion formation ta&es place by electron transfer

• The ions are held together by the electrostatic

force of the opposite charges

• /eactions between metals and nonmetals

"representative elements# tend to be ionic


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Ion $rrangement in a Crystal

• $s a sodium atom loses one electron% it becomes asmaller sodium ion

• 2hen a chlorine atom gains that electron% it becomes a larger chloride ion

• $ttraction of the a cation with the Cl anionforms aCl ion pairs that aggregate into a crystal

3 . 1 C h

e m i c a l

B o n d i n g


11/87

3 . 1 C

h e m i c a

l B o n d i n g Covalent Bonding

et8s loo& at the formation of 940

9 6 9 94• 'ach hydrogen has one electron in its valance shell• If it were an ionic bond it would loo& li&e this0

• 9owever% both hydrogen atoms have an e:ualtendency to gain or lose electrons

• 'lectron transfer from one 9 to another usually willnot occur under normal conditions

[ ]−+ +→⋅+⋅ 09999


12/87

3 . 1 C

h e m i c a

l B o n d i n g

The shared

electron

pair is called a

Covalent Bond

'ach hydrogen

atom now has twoelectrons around it

and attained a 9e

configuration

• Instead% each atom attains a noble gas

configuration by sharing electrons

909 9 9 →⋅+⋅


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Covalent Bonding in 9ydrogen

3 . 1 C

h e m i c a

l B o n d i n g


14/87

3 . 1 C

h e m i c a

l B o n d i n g

0

..

..10

..

..100

..

..1

..

..10 →⋅+⋅

'ach fluorine is

surrounded by ;

electrons + e

configuration

eatures of Covalent Bonds

• Covalent bonds form between atoms withsimilar tendencies to gain or lose electrons

• Compounds containing covalent bonds are

called covalent compounds or molecules• The diatomic elements have completely

covalent bonds "totally e:ual sharing#

+ 94% 4%


15/87

90

..

..


16/87

3 . 1 C

h e m i c a

l B o n d i n g

,olar Covalent Bonding and

'lectronegativity

• The ,olar Covalent Bond

+ Ionic bonding involves the transfer of

electrons + Covalent bonding involves the sharing of

electrons

+ Polar covalent bonding - bonds made upof unequally shared electron pairs


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3 . 1 C

h e m i c a

l B o n d i n g

These two

electrons are

not shared e:ually

somewhat negatively chargedsomewhat positively charged

0..090

..9

⋅⋅

→

⋅⋅

⋅+⋅

• The electrons spend more time with fluorine

• This sets up a polar covalent bond• $ truly covalent bond can only occur when

both atoms are identical


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,olar Covalent Bonding in 2ater

• ygen is electron rich @ δ-

• 9ydrogen is electron

deficient @ δ6

• This results in une:ual

sharing of electrons in the

pairs @ polar covalent bonds

• 2ater has 4 covalent bonds

3 . 1 C

h e m i c a

l B o n d i n g


19/87

'lectronegativity

• Electronegativity - a measure of theability of an atom to attract electrons in a

chemical bond

• 'lements with high electronegativity havea greater ability to attract electrons than do

elements with low electronegativity

• Consider the covalent bond as competition

for electrons between 4 positive centers + The difference in electronegativity determines

the e>tent of bond polarity 3 . 1 C

h e m i c a

l B o n d i n g

'l t ti iti f ! l t d


20/87

3 . 1 C

h e m i c a

l B o n d i n g

electronegativity increases e l e c t r o n e g a t i v i t y i n c r e a s e s

'lectronegativities of !elected

'lements

• The most electronegative elements are found in the upper rightcorner of the periodic table

• The least electronegative elements are found in the lower leftcorner of the periodic table


21/87

3 . 1 C

h e m i c a

l B o n d

i n g 'lectronegativity Calculations

• The greater the difference in electronegativity between two atoms% the greater the polarity of

their bond

• 2hich would be more polar% a 9- bond or 9-Cl

bondA

• 9- =. - 4.1 @ 1.D

• 9-Cl 3. - 4.1 @ .D• The 9 bond is more polar than the 9Cl bond


22/87

3.4 aming Compounds and

2riting ormulas of Compounds

• Nomenclature - the assignment of a correct

and unambiguous name to each and everychemical compound

• Two naming systems0

+ ionic compounds

+ covalent compounds


23/873 . 4 - a m

i n g C o m p o u n d

s a n d

2

r i t i n g o r m u l a s o f C o m p o u n d s ormulas of Compounds

• $ formula is the representation of thefundamental compound using chemical

symbols and numerical subscripts

+ The formula identifies the number and typeof the various atoms that ma&e up the

compound unit

+ The number of li&e atoms in the unit is

shown by the use of a subscript + ,resence of only one atom is understood

when no subscript is present


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i n g C o m p o u n d s a n d

2

r i t i n g o r m u l a s o f C o m p o u n d s Ionic Compounds

• Eetals and nonmetals usually react to formionic compounds

• The metals are cations and the nonmetals

are anions• The cations and anions arrange themselves

in a regular three-dimensional repeatingarray called a crystal lattice

• ormula of an ionic compound is thesmallest whole-number ratio of ions in thesubstance


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2

r i t i n g o r m u l a s o f C o m p o u n d s 2riting ormulas of Ionic Compounds

from the Identities of the Component Ions

• etermine the charge of each ion

+ Eetals have a charge e:ual to group number

+ onmetals have a charge e:ual to the group

number minus eight

• Cations and anions must combine to give a

formula with a net charge of 7ero

• It must have the same number of positive

charges as negative charges


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2

r i t i n g o r m u l a s o f C o m p o u n d s ,redict ormulas

,redict the formula of the ionic compoundsformed from combining ions of the

following pairs of elements0

1. sodium and o>ygen

4. lithium and bromine

3. aluminum and o>ygen

=. barium and fluorine

2 i i f I i C d


27/87

4

3 . 4 - a m


2

r i t i n g o r m u l a s o f C o m p o u n d s 2riting ames of Ionic Compounds

from the ormula of the Compound

• ame the cation followed by the nameof the anion

• $ positive ion retains the name of the

element5 change the anion suffi> to-ide

2 iti f I i C d


28/873 . 4 - a m


2

r i t i n g o r m u l a s o f C o m p o u n d s 2riting ames of Ionic Compounds

from the ormula of the Compound

• If the cation of an element has several ions ofdifferent charges "as with transition metals# use a/oman numeral following the metal name

• /oman numerals give the charge of the metal

• '>amples0

• eCl3 is iron"III# chloride

• eCl4 is iron"II# chloride

• Cu< is copper "II# o>ide


29/87


30/87

!toc& and Common ames for

Iron and Copper Ions

3 . 4 - a m


2

r i t i n g

o r m u l a s o f C o m p o u n d s


31/873 . 4 - a m


2

r i t i n g


Common Eonatomic Cations

and $nions

• Monatomic ions - ions consisting of a

single charged atom


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2

r i t i n g

o r m u l a s o f C o m p o u n d s ,olyatomic Ions

• Polyatomic ions - ions composed of 4 ormore atoms bonded together with anoverall positive or negative charge

+ 2ithin the ion itself% the atoms are bondedusing covalent bonds

+ The positive and negative ions will be bonded to each other with ionic bonds

• '>amples0

• 9=6 ammonium ion

• !


33/873 . 4 - a m


2

r i t i n g

o r m u l a s o f C o m p o u n d sCommon ,olyatomic Cations and

$nions


34/873 . 4 - a m


2

r i t i n g


ame These Compounds

1. 9=Cl

4. Ba!


35/873 . 4 - a m


2

r i t i n g

o r m u l a s o f C o m p o u n d s2riting ormulas of Ionic Compounds

rom the ame of the Compound

• etermine the charge of each ion

• 2rite the formula so that the resulting

compound is neutral

• '>ample0

Barium chloride0

Barium is 64% Chloride is -1ormula is BaCl4

t i th l


36/873 . 4 - a m


2

r i t i n g

o r m u l a s o f C o m p o u n d s etermine the ormulas rom

ames

2rite the formula for the following ionic

compounds0

1. sodium sulfate

4. ammonium sulfide

3. magnesium phosphate

=. chromium"II# sulfate


37/873 . 4 - a m


2

r i t i n g

o r m u l a s o f C o m p o u n d s Covalent Compounds

• Covalent compounds are typically formedfrom nonmetals

• Molecules - compounds characteri7ed by

covalent bonding• ot a part of a massive three-dimensional

crystal structure

• '>ist as discrete molecules in the solid% li:uid%and gas states


38/873 . 4 - a m


2

r i t i n g

o r m u l a s o f C o m p

o u n d s

aming Covalent Compounds

1. The names of the elements are writtenin the order in which they appear inthe formula

4. $ prefi> indicates the number of each&ind of atom


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3. If only one atom of a particular element is

present in the molecule% the prefi> mono- isusually omitted from the first element

'>ample0 C< is carbon mono>ide

=. The stem of the name of the last element isused with the suffi> +ide

F. The final vowel in a prefi> is often dropped before a vowel in the stem name

3 . 4 - a m


2

r i t i n g

o r m u l a s o f C o m p

o u n d s aming Covalent Compounds

Th C l C d


40/873

. 4 - a m


2

r i t i n g

o r m u l a s

o f C o m p

o u n d s ame These Covalent Compounds

1. !i


41/87

4

3

. 4 - a m


2

r i t i n g

o r m u l a s

o f C o m p

o u n d s 2riting ormulas of Covalent

Compounds• *se the prefi>es in the names to determine the

subscripts for the elements

• '>amples0• nitrogen trichloride Cl3• diphosphorus pento>ide ,4


42/873

. 4 - a m


2

r i t i n g

o r m u l a s

o f C o m p

o u n d s ,rovide ormulas for These

Covalent Compounds

1. nitrogen mono>ide

4. dinitrogen tetro>ide

3. diphosphorus pento>ide

=. nitrogen trifluoride


43/87

3.3 ,roperties of Ionic and

Covalent Compounds• ,hysical !tate

+ Ionic compounds are usually solids at room

temperature + Covalent compounds can be solids% li:uids% and

gases

• Eelting and Boiling ,oints + Melting point - the temperature at which a

solid is converted to a li:uid

+ Boiling point - the temperature at which ali:uid is converted to a gas


44/87

,hysical ,roperties

•Eelting and Boiling ,oints + Ionic compounds have much higher melting points

and boiling points than covalent compounds

+ $ large amount of energy is re:uired to brea& the

electrostatic attractions between ions + Ionic compounds typically melt at several hundred

degrees Celsius

• !tructure of Compounds in the !olid !tate

+ Ionic compounds are crystalline + Covalent compounds are crystalline or amorphous +

having no regular structure

3 . 3 , r o p e r t i e s o f I o n i c a n d

C o v a

l e n t C o

m p o u n

d s


45/87

• !olutions of Ionic and Covalent

Compounds

+ Ionic compounds often dissolve in water%

where they dissociate - form positive and

negative ions in solution + Electrolytes - ions present in solution

allowing the solution to conduct electricity

+ Covalent solids usually do not dissociate anddo not conduct electricity - nonelectrolytes

,hysical ,roperties

3 . 3 , r o p e r t i e s o f I o n i c a n d

C o v a

l e n t C o

m p o u n

d s

C i f I i C l t


46/87

Comparison of Ionic vs. Covalent

Compounds

Ionic Covalent

Composed of Eetal 6 nonmetal 4 nonmetals

'lectrons Transferred !hared

,hysical state !olid H crystal $ny H crystal


47/87

3.= rawing ewis !tructures on

Eolecules and ,olyatomic Ions

Leis !tructure "uidelines

1. *se chemical symbols for the various

elements to write the s&eletal structure of

the compound

+ The least electronegative atom will be placed in

the central position

+ 9ydrogen and halogens occupy terminal positions

+ Carbon often forms chains of carbon-carbon

covalent bonds


48/87

ewis !tructure uidelines

4. etermine the number of valenceelectrons associated with each atom in

the compound

+ Combine these valence electrons todetermine the total number of valence

electrons in the compound

+ ,olyatomic cations% subtract one electron for

every positive charge + ,olyatomic anions% add one electron for

every negative charge 3 . = r a w i n g e w i s

! t r u c t u r e s o f E o l e c u

l e s


49/87

ewis !tructure uidelines

3. Connect the central atom to each of thesurrounding atoms using electron pairs

• e>t% complete octets of all the atoms

bonded to the central atom

• 9ydrogen needs only two electrons

• 'lectrons not involved in bonding are

represented as lone pairs

• Total number of electrons in the structure

must e:ual the number of valence electrons

in step 4 3 . = r a w i n g e w i s


l e s


50/87

=. Count the number of electrons you have

and compare to the number you used• If they are the same% you are finished

• If you used more electrons than you have%

add a bond for every two too many you used• Then% give every atom an octet

• If you used less electrons than you have.seelater e>ceptions to the octet rule

F. /echec& that all atoms have the octet rule

satisfied and that the total number of

valance electrons are used

3 . = r a w i n g e w i s


l e s ewis !tructure uidelines


51/87

rawing ewis !tructures of

Covalent Compoundsraw the ewis structure of carbon dio>ide% C


52/87

F. ind the number of valence electrons for eachatom and the total for the compound

1 C atom > = valence electrons @ = e- 4 < atoms > ? valence electrons @ 14 e-

1? e- total

?. *se electron pairs to connect the C to each < witha single bond

< 0 C 0 <

G. ,lace electron pairs around the atoms

# < 0 C 0 < #

This satisfies the rule for the < atoms% but not for C

rawing ewis !tructures



l e s

# #

# #

rawing ewis !tructures of


53/87

;. /edistribute the electrons moving 4 e- from each


54/87



l e s

ewis !tructures ,ractice

*sing the guidelines presented% write ewis structuresfor the following0

1. 94<

4. 93

3. C


55/87

?



l e s

ewis !tructures of

,olyatomic Ions

• ,repare ewis structures of polyatomic

ions as for neutral compounds% e>cept0

• The charge on the ion must be

accounted for when computing the

total number of valence electrons

ewis !tructure of


56/87

ewis !tructure of

,olyatomic Cations

3 . = r a w i n

g e w i s


l e s

raw the ewis structure of ammonium ion% 9=6

raw a s&eletal structure of the molecule

1. $mmonium has this structure and charge0

4. The total number of valence electrons is determined by

subtracting one electron for each unit of positivecharge

1 atom > F valence electrons @ F e-

= 9 atoms > 1 valence electron @ = e-

- 1 electron for 61 charge @ -1 e-

; e- total + istribute these ; e- around the s&eletal structure

ewis !tructure of ,olyatomic


57/87

raw the ewis structure of carbonate ion% Cygen

• This ma&es carbon the central atom

• !&eletal structure and charge04. The total number of valence electrons is determined by

adding one electron for each unit of negative charge

1 C atom > = valence electrons @ = e-

3 < atoms > ? valence electron @ 1; e- 6 4 negative charges @ 4 e-

4= e- total + istribute these e- around the s&eletal structure


$nions

3 . = r a w i n

g e w i s


l e s



58/87

raw the ewis structure of carbonate ion% C


59/87

• !ingle bond - one pair of electrons are

shared between two atoms

• Double bond - two pairs of electrons areshared between two atoms

• Triple bond - three pairs of electrons are

shared between two atoms

• Kery stable

ewis !tructure% !tability% Eultiple

Bonds% and Bond 'nergies

3 . = r a w i n

g e w i s


l e s


60/87

or.. ..


61/87

3 . = r a w i n

g e w i s


l e s ewis !tructures and /esonance

• 2rite the ewis structure of C


62/87

• '>perimental evidence shows all bonds are

the same length% meaning there is not really

any double bond in this ion

• one of theses three ewis structures e>ist%

but the actual structure is an average or

hybrid of these three ewis structures

• &esonance - two or more ewis structures

that contribute to the real structure

0

..


63/87

3 . = r a w i n

g e w i s


l e s

ewis !tructures and '>ceptions

to the 4 valence electrons @ 4 e-

4 9 atoms > 1 valence electrons @ 4 e-

total = e-

+ /esulting ewis structure09 # Be # 9 or 9 ' Be ' 9


64/87

3 . = r a w i n

g e w i s


l e s


65/87

3. '>panded octet - an element in the 3rd period or belowmay have 1 and 14 electrons around it

• '>panded octet is the most common e>ception

• Consider the ewis structure of ,F

• ,hosphorus is a third period element

1 , atom > F valence electrons @ F e-

F atoms > G valence electrons @ 3F e-

= e- total

3. istributing the electrons results in this ewis structure

3 . = r a w i n

g e w i s


l e s '>panded


66/87

3 . = r a w i n

g e w i s


l e sewis !tructures and Eolecular

eometry0 K!',/ Theory

• Eolecular shape plays a large part indetermining properties and shape

• K!',/ theory - (alance !hell Electron Pair& epulsion theory

• *sed to predict the shape of the molecules

• $ll electrons around the central atom arrangethemselves so they can be as far away fromeach other as possible + to minimi7e electronicrepulsion


67/87

3 . = r a w i n

g e w i s


l e s K!',/ Theory

• In the covalent bond% bonding electronsare locali7ed around the nucleus

• The covalent bond is directional , having

a specific orientation in space betweenthe bonded atoms

• Ionic bonds have electrostatic forces

which have no specific orientation in

space


68/87

Eolecular Bonding

• Bonding pair @ two electrons shared

by 4 atoms

+ 90<

• onbonding pair @ two electrons

belonging to 1 atom% pair not shared

+ 0

• Ea>imal separation of bonding pairs

@ = corners of a T'T/$9'/


69/87

3 . = E o

l e c u l a r

e o m e t r y

$ !table '>ception to the


70/87

3 . = E o

l e c u l a r

e o m e t r y

$nother !table '>ception to the


71/87

3 . = E o

l e c u l a r

e o m e t r y

Basic 'lectron ,air /epulsion of

a ull


72/87

3 . = E o

l e c u l a r

e o m e t r y


a ull


73/87

3 . = E o

l e c u l a r

e o m e t r y


a ull


74/87

,redicting eometric !hape *sing

'lectron ,airs

3 . = r a w i n

g e w i

s

! t r u c t u r e s o f

E o l e c u

l e s

Basic ,rocedure to etermine


75/87

3 . = r a w i n

g e w i

s


E o l e c u

l e s Eolecular !hape

1. 2rite the ewis structure

4. Count the number of shared electron pairs andlone pairs around the central atom

3. If no lone pairs are present% shape is0• 4 shared pairs - linear • 3 shared pairs - trigonal planar

• = shared pairs - tetrahedral

=. oo& at the arrangement and name the shape• inear • Trigonal planar • Bent• Trigonal pyramid• Tetrahedral


76/87

3 . = E o

l e c u l a r e o m e t r y Eore Comple> Eolecules

Consider dimethyl ether • 9as 4 different central atoms0

• o>ygen

• carbon

+ C93 "methyl group# has tetrahedral geometry "li&e methane#

+ Portion o) the molecule lin*ing the to methyl groups ould bond angles similar to ater

etermine the Eolecular


77/87

3 . = r a w i n

g e w i

s


E o l e c u

l e s etermine the Eolecular

eometry

• ,Cl3

• !


78/87

3 . = r a w i n

g e w i

s


E o l e c u

l e s ewis !tructures and ,olarity

•$ molecule is polar if its centers of positive andnegative charges do not coincide

• ,olar molecules when placed in an electric fieldwill align themselves in the field

• Eolecules that are polar behave as a dipole "havingtwo (poles) or ends#

•


79/87

,ositive end of the

bond% the less

electronegative atom

egative end of the bond%

more electronegative atom

attracts the electrons more

strongly towards it 3 . = r a w i n

g e w i

s


E o l e c u

l e s etermining ,olarity

To determine if a molecule is polar0• 2rite the ewis structure

• raw the geometry

• *se the following symbol to denote the polarityof each bond

,ractice etermining ,olarity


80/87

3 . = r a w i n

g e w i

s


E o l e c u

l e s ,ractice etermining ,olarity

etermine whether the following bonds and

molecules are polar0

1. !i + Cl 1.


81/87

3.F ,roperties Based on 'lectronic

!tructure and Eolecular eometry

• Intramolecular forces + attractive forces

within molecules + Chemical bonds

• Intermolecular forces + attractive forces

between molecules

• Intermolecular forces determine many

physical properties

+ Intermolecular forces are a direct conse:uence

of the intramolecular forces in the molecules

n i c t r y !olubility and Intermolecular


82/87

!olubility - the ma>imum amount of solutethat dissolves in a given amount of solventat a specific temperature

• (i&e dissolves li&e) + ,olar molecules are most soluble in polar

solvents

+ onpolar molecules are most soluble in

nonpolar solvents• oes ammonia% 93% dissolve in waterA

• es% both molecules are polar

3

. F , r o p e

r t i e s B a s

e d o n ' l e c t r o n

!

t r u c t u r e

a n d E o l e c u l a r e o m e t

!olubility and Intermolecular

orces

n i c t r y Interaction of 2ater and


83/87

3

. F , r o p e

r t i e s B a s


!

t r u c t u r e


$mmonia

• The δ- end of ammonia% % is attracted to the δ6 end ofthe water molecule% 9

• The δ6 end of ammonia% 9% is attracted to the δ- end ofthe water molecule% <

• The attractive forces% called hydrogen bonds% pullammonia into water% distributing the ammonia moleculesthroughout the water% forming a homogeneous solution

n i c t r y Interaction of 2ater and


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a n d E o l e c u l a r e o m e t Interaction of 2ater and )

• 2hyA

+ Because water is polar and

oil is nonpolar

• 2ater molecules e>ert their

attractive forces on other water

molecules

•


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g :

and Eelting ,oints of !olids

• 'nergy is used to overcome the

intermolecular attractive forces in a

substance% driving the molecules into a less

associated phase

• The greater the intermolecular force% the

more energy is re:uired leading to

+ 9igher melting point of a solid

+ 9igher boiling point of a li:uid

n i c t r y actors Influencing Boiling and


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g g

Eelting ,oints

• !trength of the attractive force holding the

substance in its current physical state

• Eolecular mass

• arger molecules have higher m.p. and b.p. than

smaller molecules as it is more difficult to convert a

larger mass to another phase

• ,olarity• ,olar molecules have higher m.p. and b.p. than

nonpolar molecules of similar molecular mass due to

their stronger attractive force

n i c t r y Eelting and Boiling ,oints +


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a n d E o l e c u l a r e o m e t Eelting and Boiling ,oints

!elected Compounds by Bonding Type

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