Increase your knowledge in Physical Chemistry

Increase your knowledge in Physical Chemistry

1. O Atoms Molecules and Fiat

PHYSICAL CHEMISTRY

[ATOM

—¡An_alem is the gmallesl particle of matlen Jhal can

take pact in a reaction, li has a very gwall ma

CDALTONS Atome Theory

Atoms are very small u
Atoms are indivisible (not able do be separated )

Atoms combine in whole numberg catios do form compound

lator

¡SHORTFALLS E

> [Atoms can be broken doma do form sub-alomic particles in

lprotons, nevteons and electron 4

> When atoms combine they don’t form compound atom
but they fore molecule 2

>[Molscute The smallest worte Jul snake’ ve

RELATIVE ATome MAG E

[The symbol is Bey is the! average mass of all th

lisolopes that mahe vp an element calculated: relativ.

to the mass of the carbon-12 isolop

RELATIVE MOLECULAR Mass a
The symbol th at p
masses ef all the Eur Em

us sense, A eek raue +

SE ON aah Pr —

2. RELATIVE FORMULAR MASS |
u AA lecvlar mass bud it pay +
~zemoound LH iy athe sul of ah —

= TUE is sia

| pelis lo

vapound
mpounds, lg bu Es =

Pre Moe
(= [His the amount of a substance that contains Ah
lsyegadro sn of particles Avonada conter Se
6,02 X10” particlec , These particles can be atows,
ions or wolecules One mole of a substane tains

the relative molecular mass of Ahat compound L

IMASS SPECTRUM OF A NATURALLY OCCURING SAMPLE
lof CHLORINE _

NET CE TEE PAPA

ast Ele

5 15 37
rife

Aboadanee

USES OF MASS SPECTROMETER
1. [Used to ealeviate the Ar of an element
a> [used +0 calevlate Mr of a compound
1: [Gives vs information abovs the wurben of isotopes la
a asturally occuring sample of an element -
Y, [Tells us Information about the % abundance of each ieh
Le a naturally occuring sample
sl

3. EM identifies compounds and used in forensic science

LExangle 0000
|Caleulake the Ar of CL

——{specteven peevéously dr

Solvbian, —

Ar of a AAA] _

100

= 355

[Pass spechrum of Ne shown below, Calculale Ar of Ne
1 T

EE
of peak

tte
pa

GE

Er = -

al

Cys x20) + (o) AD) '

ns +

|

202 < a LH

MOLECULAR SPECTRUM . an on gh
Molecvles of: a nadurally reccuring sample can: alse be analysed
Jung a mass spachrometeriln the mass spectrometer the

compound is vapourised and jonised do molecular Sons. he

4. — x pegks =

The figuer_belon ches a cimglified version o
[mass aprctrum of efligaol (MC) , Explain the origin of —

| y ve 20 te atl, ba

The peak at Mie = 23 ts dos to Chet
[ine pak at Me - 29 fs due do Cac

The peak at Mie - 4S Ss due to gy ch,cHot

= [these peaks correspond to the formation of molecular

feagmerts formed when CH,CH,0H breaks

} =

3 [An organic compound has composition by mass that is € 663%

1 IH n1%; 0 2,2%) ds mass spacheum ts shows below la
Î

compoond ir de d_by due oxidation of am alcohol soft it

[thought to aldehyde (=cho group) or a ketone,"
ICalevlate me dt foceryla_of the compound, Irterprde —

[the peaks of the mass to give the molecularnformula of

Le compound,

5. [soho

nn a yon —
= Retetive ———}— e—
E 20. u
: ut | Tape
a #
u | Pomo enr
ent
— 15 _
+ |
T + 41
| 2 v6 de A
|
E Hote O7TA O
66,9 py ma
-— Y 1%
|
3,56 y DIF
1,387 17475 318%
4 g 1
Empieical formula = CyHgO =
The peak with the gmatest Mie ratio 35 due do the
molecular formula 2 y
slo molewlar formula = CH¿CR,CH, €
As A
EMPIRICAL FORMULAE
= |The empiciea) formula of a compound is the simplect formula
which represents a compound, H shows the elements present

land the radio of the amount of atoms present

T
|
T
Pees: |

A

6. mA
|
much _
4 MOLECULAR FORMUL: Fa
LR A A Gt Yam)
i Ty ix dog simple molle of the empineal fore Pye

is given by —

lis gi -

Mx empicical formula NS]
~

> pane cule?”
wula of glucose 35 CoMo Ciela

— +

ne ampiescal foremiar fs CHO | . 2

Ce!
ae 6 which is Foe way ple

= [Therefore from the eagle foule above fat
| Mmelzwlar formula, empiricl focmwvla dad _muldvple n ce

be determined.

>|Aloms are sphecical in ape. They are made op of

cote: Jectrons and _nevt:

0 ATOMIC STRUCTURE

ARTICLE [Revavive charge [rerasive mass — Locarom
Etadron ) In orbits amd]

1840 Hoe nocleas
p |Peoton +) 1 modus |
INevteon o 1 mes |
|

| ” y

BEHAVIOUR OF BEAMS OF ELECTRONS PROTON AND nevreong |
¿ELECTRIC F)EUD
|

|

7. Electron:

PAT

= Electeons are defleckd do the rudes that than
„nat _they carry a negative charge .Y they carey a

: El

— negative charge they must be deflected to the anode
Peotons aro deflected towards the eathede, This shows

Hhab dns proton: have a positive charge, Nevtrons are
jack deflected because they do not carry a charge. the
— magustvde of deflection of the electrons js mar than
that of the protons This shows that electrons are telat

[Lighter than proton, Protons are heavier
|

MAGNETIC FIELD
Etecivons are deflected in a direction thal chews that
ey have a negative chai

un 2 ==

A

ZA

neutrons

JDISTRIBUTION OF MASS AND CHARGES WITHIN AN ATOM

= Nucleus has positive charge ,The mass of He atom i
¡cencentraled jo he nveleus, The nuclous contain protons, and
neutrons. Nevicons hdve no chargé, Électrons are found 14 _

8. A guceouading “He vada zus Élecirons occupy
_jn an atom, The nucleus only occupies

Abs aora Th space euereuneting th
charged and occupies a large space, |

T

|
1607 OPES, F

These ace atoms of dhe same element. They have the

¿same number of protons and electrons but they dhffer [7

ja Abeje number of nevirers, Therefore thee mass numbers |”

lalso Kf fee, Isotopes have similar chemical properties since

hey am atoms of the came element becos they have

[He same number of electrons, Electrons determine the

[chemped) properties of elements lsotopes have different

4 hysical wropacties

ELECTRONIC CONFIGURATION

Tis is the arrangement of electrons around 4h; leu

of an atom. Électrons are arranged is shell

la shells there are = —

Pat => 1 subsmells ls

Par > % subshalj, Is 2p

Pad > 3 shell ds Ip Sd 9 ]

In the sub-shells they are orbitals, An orbital is a space —

around the nucleuc of an atom, where there 35. logs sh

9. bability Lo find ay electron,

Is > | obítal A
As — |

[P sone, > 3 orbitals E
1d sobshelli > 5 orbitals [I

Orbital; ina sobchel) are of the came energy (degamerate).
Each orbital ic cqpable ef holding two lactone

}
[RELATIVE ENERGIES OF SHELLS

[Fes 7
= a Coo
„ID
20
le
TT E
FT Me u

FIWNG OF ORBITALS =

= Orbilals of the lowest energy are filled First before
these of high enecqy ace filled, The ls subshell is filled
ficst before tha Is subsbell, 26 is filled fast before ap.

When _electee ls th I E
cfals before pairing occurs 3
Na 1 rst rp! 367

Ca 1 ret Apt ac? gpl Goh.

Pst as Apt st dp, METE

NI ae ap 38 Ih Ge TE
=s

10. Tstavle —

gunpes OF

ORBITALS _

6 = oe TALS

| P-ORBITALS _
They are dumbell shaped
aes 6.

psp

[ELECTRONIC CONFIGURATION OF 10M

Do 125% apt
Tu 1st 2st ppt as pt A
fet = Ist 1 ph 1s gol ys? 348
Veg a ist as ap® ast apt 4° 19° ©
[ye = 1st ast ap) act pt

| lonısaT)on Energy

Ficst donizalion exergy = 4 is Hu energy that Is ceased

aseous tons

| 0 «ar

>

+
O a

des

ao

> ia Fe

do rerrove one mole of elctrens from one role of gaseous _———
atoms de form one mele of unipécitive
Nag) > Na to) 3 e7

11. * Second ionisation anaegy — this ig toe energy Mad ir

lrequicad do remove ong mole of electrons from one mole of

wsibve gaseous fons do form ong mole of dipostive
— lgaseous Song

Malo => Mayte

AO > Apte

FACTORS INFLUENCING IONISATION ENERGIES

fxective nuclear char
| Ghielding (screening ) ef feet

2.

4.| Distance from the nuclou

[EFFECTIVE NUCLEAR CHARGE

= [heros the period jontsation energy invasor, Tess ty bacon
las we move from left to wight the nuclear charme is

Lacreasing but the distance “of outer electrons from th

auclevs remains conclaot, Across the period from Na to CL

[the positive charge (sire of nuclear charge) increases but Ihe

distance of the ovter electrons from the nuckus romaine

constant, The nucleus will exet a stronger force caving the

outer shell 4e move inwards, The atomic radius decreases

across the period. lonisation energy increases across the period

Na to ct

(Sheuong EFFET à

Down the grou: ation ener: ere as you

move dern the group, the number of shells is inéreasing_and

as they increase there 55 a tendency of ovter :she]) electrons
do be shielded from the infloerce of the nucleus by the inner

shal) electrons The distance ef the ovfer shall electrons Ledo 4b
inucleus also increases Lecce the number of shells mi) ba increas

12. LT Jiéivong Tne Grove OF ELEMENTS vsng THE JOMISA5 py
len — >
Die first four ionisation net

| 5 à
a Identify the group to mbich Ah lement balon,

AT Ind Ird 5

400 1360 14 goo 2) 000
| ny oy [5

His easler de remove dhe fret and second el
rou de ooo shone
[anak due fret and second electron: ave da ie en
[sara shel), 15% and 27° slectrons have the cam
Element % ís in group two à

array qe A
y 14 E Y

val # 560 6 160 4 5%
at us 13

Element Y is in group one

eerie

E nd q an)

57? 1819 2 260 1 800,
37 ns st

Element 2 35 in group these

eee ant as ya
E ESTO 1150 y ayo 6 #80
„a sr = a
Element Als Ins group two - er
ad à at

ÍA graph of. Log fonisation energy against. number of +
electrons comoved , js shown on the next. page ci
| ue ui À

13. Fest

Loayza fon

99 J43 wo)

Atora‘e number

First ionisalíón energy increases across the period à There Le

lan quomaly at Be and Boron, the 25 svbshell of Be fs

Ifeil therefore it js difficult to remove an electron from a

{foll_ sub-shell which Ys stable. The 2p in B is not stabl

becom it 15 not full or half full so it is easy to remove an
electos fo the sub-shell becoz $4 is not stable

- ¡Nitregen has a higher jonisatíon energy compared Ho oxygen becoz

[the 2p - sub-shell in N is half - filed „Half = = filled ocbítals

are associated with some stability, It 3 ds Hffievlt do move

lan electron from the stable sub-shell Ing tao electeons in

El me ochital ba Er of re Y ch other,
copulsion jnscegses the energy of another electron in the

syb-she)) causing if do be eactly lost

‘The following is a graph of the Log of all Ihe successive
Low sation enerqu against the ne of electrons eemoved from

a particular element

aa

14. \

Ibe first Ace electrons am easy do remove besausı

they need call amount of roy to remove » Ihe .

t
[onssation energias of the Ihree electrons ar: mida the
[same range suggesting that they ace in the same shal!

nich ts The ovter shell, Electronxe, eafiguration is

Ist ns Apt IR 2p)

15. @ CHEMICAL BONDING _

HONIG (ELECTROVALENT) Bonbıng

= lll involves transfer of electeong from one atom do arother

__|atom, Usually it eceors belneen metals a

cs between element; that have a large Lf ference in

oc.

ecleonegat vty |

lectroneg 3s the tendency of an element do pull

electrons towards itself. Some elemento have high tendencies

[Celeclronegativity) while some have low elecironegalivity

Elements auhich have the highest tendency do Lose electrons are
Ved elacteoposit ——

rin Elrehrongge

Increase so eleckopesibvids— ih

}

T | Periodic abs j

= llonic bonding is the electrostatic force of attraction between

the pastbvely and negatively charged fons. 3

COVALENT BONDING

y

[Mis is a type of bond}, ich involves sharin elecdeon,
[This type of bonding, occurs sn non-metals Occurs between

elements that have almost simslac electronegatividy They,

share electron: je inorder +o have a noble gas eledronse -
a 3

configuration on Tubjeh is stable

16. [co-oromnse nonning (KAT VE)
{Tass is a Hype of bonding which occur;
eleevlas but the shared pase of

aco-ocdinate bond has been fo
L =erd you cannot
= diffen oliate it from other bonds. A encondingtg kan 5

poc of covalent tending. in mich he shard paje >

à lectrone come from one atom in

j Na an + nu E
1 —H —
Ho Nt + a On
a FEA
| I
a
| | ==
iy a-B Net. DSB eh >
| ) 4 a 4
| a Brarrondung vores Fech

: |GHAPES OF MOLECULES 8 1

{= [Shapes of molecules can be explained una We Valen |
4 Electron Pave Repuleñon Theory (VEPRT) 1

| MAIN FEATURES OF THE “VALENCY ELECTRON PAIR REPULSION
| THEORY
i |

17. bitals oc electeons pañes orient themselves in space
saudug) copelgyony
ads behave as single bonds

betrveen =e bebreer Y epelnon bebe
bond, and lone

hodi part

aie

ING of regions of -ve charge 4 >
The molecvie assumes a delrabetral shape oth a bond angl
ef 109, 5°

>
CIA
PA
4 =
Reoiors of -ve charge are 4
The shape is expectated do be tetrahedral but becor of the

lone pair ef electrons the shape $s a distorted tetrahedcal
ashich is pyramidal, The bord angle is 109,3"

J
be, > 8
Pr cu

Region of -ve charge are 3', Bond angle is 120°
Ghape 4 4 4rrgona) planar

18. leads) bot 5 ET not, Tor shape |
of 105,5

ed +
_shape Is suppoics
pd or vend mil a bord an

te:

= D region of "Ye charge

i D is Umae are og) al 1

| F
| sh — € ss +
| | SN ‘a
1 4
N E

| £ -

shape Ys octahedra) witb a bond angle ef 90 +
1 6 regions of —ve charge
+ A 3

hapa ha deiganal bipyrarida) à Bond ange És 120° and 0°, |

5 eggjons of -ve charge 0

WE e cé

ago, Tete)

19. Tag) Prmar—

ee

=>

20. I - =
O epvacenr song In TERT or PDA wer

AAA RAE TP O =
ara bond is a single bord, His formed ARO

oeclap lesa headon. —

I)

00=

A

|

[Pi bond MT

= [Pi bonds are formed when alone orbitals ov leg

[ideways to for meleculas orbital

fi ] y DS Y =
hE I oO es =
Í
i + [ohne oF ETHENE —
Fr lem, en,
tf ‘i
ET
| ae,
| Spt my Bo ados =
Favgonal pra PSE oo
|

HH]

pese.

21. Shope of Chae TI

E
7 .

|
| Shope of Rew

| GU, Trigpnalı plarar

Sp lbniisabion electro. iS perpendlitalarto

=[OrbMal overlap Steways aloe od ido tico plane el |

ke molecule to frm a pi load

22. CONSTRUCTING 10mic EQUATIONS FOR REDOX
Redox Reachas _ —— |

ln redex maclms, oxidation and recluchen Fakes —
„place, (Sim, Haneausly), | nae

en obtined bomba adding) He

„a En equetion and. be teal agote as

__ you will see as

wet

= Dies Oda: and Nahe; of

| Oxidatian is She Jose of tes _
educhion is Ihe gain of clectrons

ZT Gusde Me redox opchn bles
INa_+ Cle “—» 1Nad

= Literalby adding these. tue us
the overall sede equation, as sham below
= Wa — IN He

AA ge x
| | Na RO > 22

Bet Fin goneral. waderctading of chen y Gad.

l'ont” “There tthe gration ends up at
MN sna !

23. [The above example was simple, and is Ihe
LE wae canal ted redox Tens

state... _
[Oxidation is the increase à oxidados stale,
| [Reduction is He decrease la onidahan state. _

TTY
=| Constder the 2 pains below 2 T
AT Fan A

He + 1

=] From © , the oxidation stale of fe increases Im,
[42 lo 8, heute is an ¡doren

de Comstructing half Tonic eg E s
“Tis involves Fre Prmato o:

| a, OX ban OF ree o:
| Couapousdl gr Con ln or ine
al Tak doar pa di aude et
= o ada, a
prachse are needed.

[Some of Me hall (onic equahoss tomb shall
Le taichnudlel ae found de your dela Goblets N

i od to be Rllased
Le Est x ae doit He in

1 show

24. e ante U2 of ctoms if Le.
_ y hoe the the = rare BER
Zar Fr vig ol à ee

TBI da alkaline Conditions roi a Whe ble sides
O he que alter sto Step 5 _
TON dd Le mot Ra hat Fre OH ac
step 6 should Le equal à net the Hin

He € half toni ¡da
ENT a ad Ae na
equahen a is Thine. #20 oppears
Lon bth sides ol the eqjucctinn
-aleleascally
Tra CE LookloL
: Rod Aigle
k Cho + CF
9. Cao = 20
3 or => 20% + Ho
¢. 20 + Hho
5 Co oe + 14H + Le + 20 + FLO

25. o

E 2 Rodada of of Moh, | __
ml ie a CM
où cru > mig + Hao

So + aH tbe —» mat + Hho

=e 2 was wot dove berges it was er rico co
y adems of Ma are alvedey al reac ready bale =a

Te Equation Olave appears de you bookle:
Ss Gbez CHCA GE ahaa E
Y PERS _ -

= 5

CHSCH, OH —>» __ cod!
Hol + Mo —>»_ HCooH
CHCHoH + HO => _CHhCooH + Gui
ChyCthoW + Ho —p Clk coo + HT
Since the reackbn o balene Hon
___ [ske 6 should be taken
a TE ~

ec dkahart to SW Cheats Whar
| A

= Having_H0 les ll calas old qu is
I make Sue wer ho negative sans app a
your Tag Talgelraic expresse y
TONY +o — CH Cody + 280 th
Lhalauced

26. ¿Example Y: vudahos of NHL d Nop

=> NO oe
— Noy —
NO + JOH"

ng; + IoHt + 8er

= iaa of he eh and reduchon equcckan,
toda spac

| ques nse ke te

Tens a

ee
> [weh the Tiedge iad a bl ad
one may Solve Has bul requires à lle reasacıg.
=| One needs to (eye ee ees
and wat à E

— Anoler—pacek fe à a
ae peter ns tal : Lee

Tess is Je ue

A Oz … > NO
45 NOT ET Er — INO + 9H, 0
j

27. (= The egpahon overleaf is the reduchon ados

TS Te oxidachion — equedien isos Follows :
a Ca > de

| | Combination of Abe : 2 ques eb a da que

BC. Ca = & + IT ss
FA [moy LH tie No Op Im

“| 3C + ano; + 8H — 3 FAN + Ho
i BZ
| + The equebón an ale is belanced, bel topo and ~
unsatis: nce it appears in tonic
= armen —

eer rear all rare
Te br Noy ask Cafes) |
-| The s Jon:
| + Ba gs mre
( | of humber.
3 ar + > HIN + HOE bie
TT uaderlined NE ions are the ones added do —

Im

34 + SHNO, — Calvo), + ano F Ty