Download - polarity-111206015735-phpapp02 Cambridge a levels chemistry

8/11/2019 polarity-111206015735-phpapp02 Cambridge a levels chemistry

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http://lawrencekok.blogspot.com

Prepared byLawrence Kok

Video Tuto r ial on Polar i ty, Hyd rogen

Bonding and Van Der Waals forces of

attract ion.
http://lawrencekok.blogspot.com/http://lawrencekok.blogspot.com/


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Polar i ty of Molecules

Electron egativity (EN) of elements Difference in EN giv es dif ference in polarit y

Fluor ine high est EN value HF mos t polardifferenc e in EN is HIGHEST

HI least po lardifference in EN is SMALLEST

Polar i ty depends on Electronegat ivi ty values


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Polar i ty also depends on shape (Symmetr ical or A symmetr ical )

Symmetr ica lNon Polar


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Polar i ty also depends on shape (Symmetr ical or A symmetr ical )

As ymmetr ical - PolarSymmetr ica lNon Polar


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Molecule with a net dipole moment w i l l have turn/spin i f placed in an electr ic f ield


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Bondin g Forces - Intramo lecular and Intermo lecular

Bonding wi th in mo lecu le

Strong bond ingTHREEtypes

1. Ionic B ond ing

2 Covalent Bonding

3 Metal l ic Bonding

1 Intermolecular forces of attraction2Intramolecular forces of attraction

Bonding between mo lecules

Weak BondingTHREEtypes

1 Temporary Dipo le (VDF)

2. Permanent Dipo le (VDF)

3 Hydrogen Bo nding


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1. Ionic B ond ing

2 Covalent Bonding


1 Intermolecular forces of attraction2Intramolecular forces of attraction





3 Hydrogen Bo nding

1


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1. Ionic B ond ing

2 Covalent Bonding


1

Bo th are Van Der Waals forc es

Intermolecular forces of attraction2Intramolecular forces of attraction





3 Hydrogen Bo nding

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Van Der Waals forc es

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Van Der Waals for ces Van Der Waals for ces

1 2


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Van Der Waals for ces Van Der Waals for ces Hydrogen Bon ding

Hydrogen Bonding1 23


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Facto rs affect ing VDF forc es of attract ion

RMM/Size

RMM up Van Der Waals up

1


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Facto rs affect ing VDF forc es of attract ion

RMM/Size Surface Area

RMM up Van Der Waals up Surface area up Van Der Waals up

1 2


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Factors affect ing the boi l ing po int of molecules

Temp orary Dipole Mom ent (VDF) Permanent Dipole Moment (DP) Hydr ogen Bondin g (HB)

1

Arrange the fo l lowing Highest to Lowest Boi l ing Point

2


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Boi l ing Point HighestH2O > CI2>N2> H2

1


2

Boi l ing Point HighestHF > HI > HBr > HCI


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3

4


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Bo i l ing Point Highest ICI > Br2


3

4Hydrogen Bond ing in CH3CH2OH

CH3CHO is polarhas dipole

interact ion

Boi l ing Point HighestCH3CH2OH > CH3CHO > C3H8


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5


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5

Boi l ing Point Highest CH3COOH > CH3CH2CH2OH > CH3CH2OH > C2H5-O-C2H5

Why b/p CH3COOH > CH3CH2CH2OH


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5

Boi l ing Point Highest CH3COOH > CH3CH2CH2OH > CH3CH2OH > C2H5-O-C2H5

Why b/p CH3COOH > CH3CH2CH2OH 1

2

3


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Expla in w hy NCI3is p olar whi le BCI3in non po lar

VS

Polar Non Polar

NCI3 BCI3


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Expla in w hy NCI3is p olar whi le BCI3in non po lar

VS

Polar Non Polar

NCI3is polar BCI3in Non po lar

NCI3 BCI3


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Why 2 Nit roph enol has lower boi l ing po int than 4 ni t rophenol ?

2 Nitrophenol 4 Nitrophenol11


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Why 2 Nit roph enol has lower boi l ing po int than 4 ni t rophenol ?

Low est b/p

>

Increase due to higher RMM

High b/p due to H2bond ing


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Which m olecule is po lar /non po lar?


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Which m olecule is po lar /non po lar?


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Which molecule has hydrogen bonding ?


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Which molecule has hydrogen bonding ?

Polar i ty of Molecu les for Cis/Trans


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Polar i ty of Molecu les for Cis/Trans

Cis b/p is HIGHERthan Trans b/pCis m/p is LOWERthan Trans m /p

WHY?


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Cis b/p is HIGHERthan Trans b/p

Trans Isom er

Trans Isomer bond po lar i ty cancelNo dipole
http://www.youtube.com/watch?v=LKAjTE7B2x0&feature=related


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Cis b/p is HIGHERthan Trans b/p

Trans Isom er

Trans Isomer bond po lar i ty cancelNo dipole

Cis Isomer

Cis Isomer bon d po lar i ty reinforce - Dipole
http://www.youtube.com/watch?v=LKAjTE7B2x0&feature=related


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Trans Isom er

Cis m/p is LOWERthan Trans m /p

m/p = -50C m/p = -80C

Trans - linear stru ctur e, greater VDF interact io n
http://www.youtube.com/watch?v=LKAjTE7B2x0&feature=relatedhttp://www.youtube.com/watch?v=LKAjTE7B2x0&feature=related


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Trans Isom er

Cis m/p is LOWERthan Trans m /p

m/p = -50C m/p = -80C

Cis Isom er

Trans - linear stru ctur e, greater VDF interact io n Cis - bend stru ctu re, less VDF interact io n
http://www.youtube.com/watch?v=LKAjTE7B2x0&feature=relatedhttp://www.youtube.com/watch?v=LKAjTE7B2x0&feature=related


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Video Tutor ia l on Hydrogen Bonding and Polar i ty

H2 Bond ing in HFH2 Bonding in H2O

Bond Polar i ty in d etai led (Good tutor ia l)

Bond Polar i ty in detai led (Good tutor ia l)
http://www.youtube.com/watch?v=LKAjTE7B2x0&feature=relatedhttp://www.youtube.com/watch?v=LKAjTE7B2x0&feature=relatedhttp://www.youtube.com/watch?v=lkl5cbfqFRM&feature=relatedhttp://www.youtube.com/watch?v=LGwyBeuVjhU


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Acknowledgements

Thanks to source of pictures and video used in this presentation

Thanks to Creative Commons for excellent contribution on licenses

http://creativecommons.org/licenses/

Prepared by Lawrence Kok

Check out more video tutor ials f rom m y si te and h ope you enjoy th is tu tor ial

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