ࡱ>  nT _ewPNG  IHDR;~n^sBIT&C`PLTEUf""U"f"DDff"ww3fffDDUUww""33U"fDDUUffwẅ̈ݙ*F tRNS\\bKGDHIDATxv0U/`P1wKKN8 BcE3R ;sOp7O.XA9?e8c[ mUB'j`"K,5 |-U3ByG={81YYWbZEhCu,gg(Ќ#cus$ c _5hi @ qc<o荏l.,(>])o*R РKh+UWV luNˑrpP bYBägz7zǀy!1o0w6̓%96SE]cC~iy:LY~H*cauK2LӒ̷X'7W؟˴LZ7N>Zs>9U{UKue'zHWUe^W\Pfil8.v8քjL,ӡd;WIJzN:kиJ_]+,,mPb`Yw*YR>tnZ~Q@m6pO*X+vDtgIu8o %;t/ukʑֽoGXuDƿ #RE]30Eg) [86}Y̝q*GM68}se!D:1Xׅ#3*GLMe-R`3wݭWœO]+CunǞ횕tvgu~Ou' >m4"JFIFKKMSO Palette C   ")$+*($''-2@7-0=0''8L9=CEHIH+6OUNFT@GHEC !!E.'.EEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE"!!1AQqa!1 ?F3]'IƓe5,J$3?O 5LXyYL4tO%fxM\DXL`: a2HS=rtd+f\UtV5m7L?cf7 `Zx5\k(   "  "Slide 3"Slide 3/ 0DTimes New Romantt. 0DArial Blackmantt. 0" DTahomalackmantt. 0"0DAriallackmantt. 0@DCourier Newmantt. 01PDVerdanaNewmantt. 0"@ .  @n?" dd@  @@`` -P0   &***    J@aa^a^IKIGJGK>hb #    8<<;;=.'(&3:2a%#  + -/01234-`$$$$$$b$bpe# zt OR$FE-Qڛb>" 0AA ff3f̙f3f@fd g4`d`d|; 02p( pY <4BdBd@w 0t.Hg4:d:ddu 0p@ pp<4!d!d@w 0t.ʚ;7ʚ;<4dddd@ x 0@r0___PPT10 pp2___PPT9/ 0? %O =hO <UTt+QVWXK{/s*>?@ABJY= P4   0` ̙33` ` ff3333f` 333MMM` f` f` 3>?" dd@,|?" dd@   " @ ` n?" dd@   @@``PR    @ ` ` p>>L0 VN (    6 P  T Click to edit Master title style! !  0   RClick to edit Master text styles Second level Third level Fourth level Fifth level!     S  0 ``  X*  0@ `   Z*  0 `   Z*z  bA޽h @ ?Parchment ̙33 Default Design 0 zr@ ( )   0\ P    P*    0]     R*  d  c $ ?    08]  @  RClick to edit Master text styles Second level Third level Fourth level Fifth level!     S  6\i `P   P*    6@n `   R*  H  0޽h ? ̙3380___PPT10.407r 0X(   $+ X X 0y P    X*  X 0}     Z*  X 6 `P   X*  X 6 `   Z* H X 0޽h ? ̙3380___PPT10.407r 0L0 P/(    089 .BORN-HABER CYCLES A guide for A level studentsB/(26f<ffJ + C "A KTRE: . , <̙? x @ 0 0 - <̙? x @ 0 0 . 0@x m OKNOCKHARDY PUBLISHING(2 f / 0`D"`>B 2008 SPECIFICATIONS>G$G   B  s *޽h ? ̙33y___PPT10Y+D=' = @B +/  0L0 >6`(    0l _BORN-HABER CYCLES2(2(f<fA  0|p INTRODUCTION This Powerpoint show is one of several produced to help students understand selected topics at AS and A2 level Chemistry. It is based on the requirements of the AQA and OCR specifications but is suitable for other examination boards. Individual students may use the material at home for revision purposes or it may be used for classroom teaching using an interactive white board. Accompanying notes on this, and the full range of AS and A2 topics, are available from the KNOCKHARDY SCIENCE WEBSITE at... www.knockhardy.org.uk/sci.htm Navigation is achieved by... either clicking on the grey arrows at the foot of each page or using the left and right arrow keys on the keyboard (2 2(2 2   75, dB  <D?e e dB  <D)@0A  0Pp@ 0 0dB @ <D)@X@  0X0@ 0 0B  s *޽h ? ̙33y___PPT10Y+D=' = @B +9 0L0 H@p (    0t, _BORN-HABER CYCLES2(2(f<f  0ܯ8  WCONTENTS Lattice Enthalpy Definition of enthalpy changes Born-Haber cycle for sodium chloride Calculation of Lattice Enthalpy Born-Haber cycle for magnesium chlorideX (202 2,DDdB  <D)@0A  0Pp@ 0 0dB  @ <D)@X@   0X0@ 0 0B  s *޽h ? ̙33y___PPT10Y+D=' = @B +  0L0    @. (  @ @ 00 FTHERE ARE TWO DEFINITIONS OF LATTICE ENTHALPY 1. Lattice Formation Enthalpy  The enthalpy change when ONE MOLE of an ionic lattice is formed from its isolated gaseous ions. Example Na+(g) + Cl(g) Na+ Cl(s) ./ fff#ffffZ         @`dB @ <DfoY dB @ <D)@0A @ 0Pp@ 0 0dB @@ <D)@X@ @ 0X0@ 0 0 @ <lje VLattice Enthalpy Definition(s) 2~ @ 0ډx 2. Lattice Dissociation Enthalpy  The enthalpy change when ONE MOLE of an ionic lattice dissociates into isolated gaseous ions. Example Na+ Cl(s) Na+(g) + Cl(g) MAKE SURE YOU CHECK WHICH IS BEING USED(#fufffff'!!Z       , dB @ <Dfo i B @ s *޽h ? ̙33y___PPT10Y+D=' = @B +  0L0   < (  < < 00 j1. Lattice Formation Enthalpy  The enthalpy change when ONE MOLE of an ionic lattice is formed from its isolated gaseous ions. Values highly EXOTHERMIC strong electrostatic attraction between oppositely charged ions a lot of energy is released as the bond is formed relative values are governed by the charge density of the ions. Example Na+(g) + Cl(g) Na+ Cl(s)  f !ff#ffffZ         @`dB < <Dfo@ dB < <D)@0A < 0Pp@ 0 0dB <@ <D)@X@ < 0X0@ 0 0 < <He VLattice Enthalpy Definition(s) 2F D >  < D  >  < 0pD 0 > uNaCl(s)((2"  fB  < 6D> lB  < <DԔ P  < 0XD @ >  $Na+(g) + Cl (g) d(2   <    fB < 6D> B < s *޽h ? ̙33y___PPT10Y+D=' = @B +  0L0   "l@ ( w l  l <Be VLattice Enthalpy Definition(s) 2  l 0M f2. Lattice Dissociation Enthalpy  The enthalpy change when ONE MOLE of an ionic lattice dissociates into isolated gaseous ions. Values highly ENDOTHERMIC strong electrostatic attraction between oppositely charged ions a lot of energy must be put in to overcome the attraction relative values are governed by the charge density of the ions. Example Na+ Cl(s) Na+(g) + Cl(g)#f~ !fffffZ        dB l <DfjJy 8 D > "lD  > l 6HpD 0 > uNaCl(s)((2"  lB l <D> rB l BDԔ V l 6_D @ >  $Na+(g) + Cl (g) d(2   <    lB l <D> dB l <D)@0A l 0Pp@ 0 0dB l@ <D)@X@ l 0X0@ 0 0B l s *޽h ? ̙33y___PPT10Y+D=' = @B + 0L0  ,(  ,dB , <D)@0A , 0Pp@ 0 0dB ,@ <D)@X@ , 0X0@ 0 0  , <neU TCalculating Lattice Enthalpy 2k  , 0s"`0 iSPECIAL POINTS you CANNOT MEASURE LATTICE ENTHALPY DIRECTLY it is CALCULATED USING A BORN-HABER CYCLE d[)f$f j B , s *޽h ? ̙33y___PPT10Y+D=' = @B +y 0L0 D(  DdB D <D)@0A D 0Pp@ 0 0dB D@ <D)@X@ D 0X0@ 0 0 D <,eU TCalculating Lattice Enthalpy 2 D 0"`0 SPECIAL POINTS you CANNOT MEASURE LATTICE ENTHALPY DIRECTLY it is CALCULATED USING A BORN-HABER CYCLE greater charge densities of ions = greater attraction = larger lattice enthalpy Y!!!  B D s *޽h ? ̙33y___PPT10Y+D=' = @B +w 0L0 ~ H(  HdB H <D)@0A H 0Pp@ 0 0dB H@ <D)@X@ H 0X0@ 0 0 H <eU TCalculating Lattice Enthalpy 2 H 0d"`0Y SPECIAL POINTS you CANNOT MEASURE LATTICE ENTHALPY DIRECTLY it is CALCULATED USING A BORN-HABER CYCLE greater charge densities of ions = greater attraction = larger lattice enthalpy Effects Melting point the higher the lattice enthalpy, the higher the melting point of an ionic compound Solubility solubility of ionic compounds is affected by the relative values of Lattice and Hydration Enthalpies!!&<   ] B H s *޽h ? ̙33y___PPT10Y+D=' = @B +  0L0  0 L(  L L 0 < Cl Br F O2- Na+ -780 -742 -918 -2478 K+ -711 -679 -817 -2232 Rb+ -685 -656 -783 Mg2+ -2256 -3791 Ca2+ -2259XPx  33ffff3f3f3 @  G  2  L <e OLattice Enthalpy Values 2 L 0š~  Smaller ions will have a greater attraction for each other because of their higher charge density. They will have larger Lattice Enthalpies and larger melting points because of the extra energy which must be put in to separate the oppositely charged ions.l@ ! !!! dB L <D)@0A L 0Pp@ 0 0dB L@ <D)@X@ L 0X0@ 0 0 L 0Κ iUnits: kJ mol-1* 2    B L s *޽h ? ̙33y___PPT10Y+D=' = @B +( 0L0 7/$ (    0 V Cl Br F O2- Na+ -780 -742 -918 -2478 K+ -711 -679 -817 -2232 Rb+ -685 -656 -783 Mg2+ -2256 -3791 Ca2+ -2259rPx  33ffff3f3f3 @  G  2   <e OLattice Enthalpy Values 2   0~  USmaller ions will have a greater attraction for each other because of their higher charge density. They will have larger Lattice Enthalpies and larger melting points because of the extra energy which must be put in to separate the oppositely charged ions.@ 8 1Z   K  f2   611Z    0 ' C  ClD(2"  8   ?   2 `2   01  ?   0E   uNa+: 2   F 1Z    7 o f2  611Z    0' C  ClD(2"  |  0Xp Xx The sodium ion has the same charge as a potassium ion but is smaller. It has a higher charge density so will have a more effective attraction for the chloride ion. More energy will be released when they come together. & 2 8   b   7 8 `2  01  b   6h%7 Z  tK+: 2   dB  <D)@0A   0Pp@ 0 0dB !@ <D)@X@ " 0X0@ 0 0B  s *޽h ? ̙33y___PPT10Y+D=' = @B +G  0L0 V N  ( w   <ٚe  $Born-Haber Cycle For Sodium Chloride% 2%.   dB  <D)@0A  0Pp@ 0 0dB @ <D)@X@  0X0@ 0 0  0,0  & kJ mol-1 Enthalpy of formation of NaCl Na(s) + Cl2(g)   > NaCl(s)  411 Enthalpy of sublimation of sodium Na(s)   > Na(g) + 108 Enthalpy of atomisation of chlorine Cl2(g)   > Cl(g) + 121 Ist Ionisation Energy of sodium Na(g)   > Na+(g) + e + 500 Electron Affinity of chlorine Cl(g) + e   > Cl(g)  364 Lattice Enthalpy of NaCl Na+(g) + Cl(g)   > NaCl(s) ?@@ !!! |  A :*    !,      1     D           7    $          B  s *޽h ? ̙33y___PPT10Y+D=' = @B +  0L0 %  ah  (  h h <te Born-Haber Cycle - NaCl,(2, dB h <D) v dB  h <D)jB 'h BDo 2 ,h 6t x  71} Gh B4t̙))?"`e   This is an exothermic process so energy is released. Sodium chloride has a lower enthalpy than the elements which made it. VALUE = - 411 kJ mol-1P{ 2(2{ dB Hh <D)@0A Ih 0Pp@ 0 0dB Jh@ <D)@X@ Kh 0X0@ 0 0 Nh 04)t ^F  Na(s) + Cl2(g) F(2      "   Oh 00tg  NaCl(s)6(2   "  2 [h <6tH  Enthalpy of formation of NaCl Na(s) + Cl2(g)   > NaCl(s) @%Px@ff Z       2 \h 0Gt! E1(  B h s *޽h ? ̙33y___PPT10Y+D=' = @B +6 0L0 E=0;(  jB  BDo  dB   <D) v dB   <D> v dB   <D)jB  BDo 2  6Nt x  712  6[t A(  72 ' BTbt̙))?"`e   This is an endothermic process. Energy is needed to separate the atoms. Sublimation involves going directly from solid to gas. VALUE = + 108 kJ mol-1P 2(2 dB ( <D)@0A ) 0Pp@ 0 0dB *@ <D)@X@ + 0X0@ 0 0 . <lte Born-Haber Cycle - NaCl,(2,  / 0Zt ^F  Na(s) + Cl2(g) F(2      "   0 0ztg  NaCl(s)6(2   "    1 08tZ ^  Na(g) + Cl2(g) R(2       "   5 <ttH  Enthalpy of formation of NaCl Na(s) + Cl2(g)   > NaCl(s) Enthalpy of sublimation of sodium Na(s)   > Na(g) @%Px#@Px@ff !f      %      2 6 0Dt! E1(  2 7 0t!s E2(  B  s *޽h ? ̙33y___PPT10Y+D=' = @B + 0L0 @;e( w jB  BDo  dB   <D) v dB   <D>vdB   <D> v dB   <D)jB  BDo jB  BDo 2  6Шt x  712  6Hts  732  6t A(  72 ' B(t̙))?"`e  j Breaking covalent bonds is an endothermic process. Energy is needed to overcome the attraction the atomic nuclei have for the shared pair of electrons. VALUE = + 121 kJ mol-1P 2(2 dB ( <D)@0A ) 0Pp@ 0 0dB *@ <D)@X@ + 0X0@ 0 0 . <te Born-Haber Cycle - NaCl,(2,  / 0t ^F  Na(s) + Cl2(g) F(2      "   0 0ptg  NaCl(s)6(2   "    1 0tZ ^  Na(g) + Cl2(g) R(2       "   2 0tVL j Na(g) + Cl(g) B(2     <    B 5 <wH  pEnthalpy of formation of NaCl Na(s) + Cl2(g)   > NaCl(s) Enthalpy of sublimation of sodium Na(s)   > Na(g) Enthalpy of atomisation of chlorine Cl2(g)   > Cl(g) @%Px#@Px%@Px@ff !f#f       %     8   2 6 0w! E1(  2 7 0w!s E2(  2 8 0t!k E3(  B  s *޽h ? ̙33y___PPT10Y+D=' = @B + 0L0 P:*( w   <#we Born-Haber Cycle - NaCl,(2, jB  BDo  dB   <D) v dB   <D>vdB   <D> v dB   <D)dB   <D>/jB  BDo jB  BDo((jB  BDo 2  6|-w x  712  6T1w^ 742  65ws  732  64w A(  72 ' B NaCl(s) Enthalpy of sublimation of sodium Na(s)   > Na(g) Enthalpy of atomisation of chlorine Cl2(g)   > Cl(g) Ist Ionisation Energy of sodium Na(g)   > Na+(g) + e  @%Px#@Px%@Px!@Px@ff !f#f f        %     8           2 5 0Dyw! E1(  2 6 0qw!s E2(  2 7 0w!k E3(  2 8 0w!S E4(  B  s *޽h ? ̙33y___PPT10Y+D=' = @B + 0L0 +#`#:( w   <we Born-Haber Cycle - NaCl,(2, jB  BDo  dB   <D) v dB   <D>vdB   <D> v dB   <D)dB   <D>/dB  <D>jB  BDo jB  BDo((jB  BDo jB  BDo\\2  6سw x  712  6wX& 752  6 NaCl(s) Enthalpy of sublimation of sodium Na(s)   > Na(g) Enthalpy of atomisation of chlorine Cl2(g)   > Cl(g) Ist Ionisation Energy of sodium Na(g)   > Na+(g) + e Electron Affinity of chlorine Cl(g) + e   > Cl(g) @%Px#@Px%@Px!@Px @ Px@ff !f#f f  f*      %     8         +     2 5 0 x! E1(  2 6 0x!s E2(  2 7 0w!k E3(  2 8 0`Bx!S E4(  2 9 0TIx !S  E5(  B  s *޽h ? ̙33y___PPT10Y+D=' = @B +! 0L0   &<d (    <H>xe Born-Haber Cycle - NaCl,(2, jB  BDo  dB   <D) v dB   <D>vdB   <D> v dB   <D)dB   <D>/dB  <D>jB  BDo jB  BDo((jB  BDo jB  BDo\\2  6hUx x  712  6@Yx `(  762  6]xX& 752  6_x^ 742  6cxs  732  6hx A(  72dB  @ <DodB ) <D)@0A * 0Pp@ 0 0dB +@ <D)@X@ , 0X0@ 0 0 / 0x ^F  Na(s) + Cl2(g) F(2      "   0 0sxg  NaCl(s)6(2   "    1 0xxZ ^  Na(g) + Cl2(g) R(2       "   2 0xVL j Na(g) + Cl(g) B(2     <    1 3 0x /I Na+(g) + Cl(g) `(2        <    R 4 0xk` $Na+(g) + Cl (g) n 2          <    " 5 <pxH <  Enthalpy of formation of NaCl Na(s) + Cl2(g)   > NaCl(s) Enthalpy of sublimation of sodium Na(s)   > Na(g) Enthalpy of atomisation of chlorine Cl2(g)   > Cl(g) Ist Ionisation Energy of sodium Na(g)   > Na+(g) + e Electron Affinity of chlorine Cl(g) + e   > Cl(g) Lattice Enthalpy of NaCl Na+(g) + Cl(g)   > NaCl(s) @%Px#@Px%@Px!@Px @ Px@"Pxff !f#f f  ff        %     8         +              2 6 0px! E1(  2 7 0Dx!s E2(  2 8 0x!k E3(  2 9 0\x!S E4(  2 : 0|x !S  E5(  2 ; 0x !H  E6(    < Bx̙))?"`   ULattice Enthalpy is exothermic. Oppositely charged ions are attracted to each other.V 2VB  s *޽h ? ̙33y___PPT10Y+D=' = @B + 0L0 &` 0 b(      <xe Born-Haber Cycle - NaCl,(2, dB   <Do  ^B   6D) v ^B   6D>v^B   6D> v ^B   6D)^B   6D>/^B   6D>dB   <Do dB   <Do((dB   <Do dB   <Do\\2   0y x  712   04 y `(  762   0yX& 752   0y^ 742   0ys  732   0y A(  72   0y ^F  Na(s) + Cl2(g) F(2      "     0,&yg  NaCl(s)6(2   "      0*yZ ^  Na(g) + Cl2(g) R(2       "     01yVL j Na(g) + Cl(g) B(2     <    1   009y /I Na+(g) + Cl(g) `(2        <    R   0HAyk` $Na+(g) + Cl (g) n 2          <    dB  @ <Do  &  0Jy\e  dCALCULATING THE LATTICE ENTHALPY Apply Hess s Law,3 2"fdB A  <D)@0A B  0Pp@ 0 0dB C @ <D)@X@ D  0X0@ 0 02 T  0Ryy 4 712 U  0HVyE< 762 V  0 Zy4 752 W  0SyS< 742 X  0bya< 732 Y  0ey< 72 Z  0iy[e  w = - - - - + The minus shows you are going in the opposite direction to the definition = - (-364) - (+500) - (+121) - (+108) + (-411) = - 776 kJ mol-1 v 2C 2)  B   s *޽h ? ̙33y___PPT10Y+D=' = @B +! 0L0   @,,P (  P P < vye Born-Haber Cycle - NaCl,(2, dB P <Do  ^B P 6D) v ^B P 6D>v^B P 6D> v ^B P 6D)^B P 6D>/^B  P 6D>dB  P <Do dB  P <Do((dB  P <Do dB  P <Do\\2 P 0y x  712 P 0ty `(  762 P 0yX& 752 P 0\y^ 742 P 0ys  732 P 0xy A(  72 P 0y ^F  Na(s) + Cl2(g) F(2      "   P 0Xyg  NaCl(s)6(2   "    P 0yZ ^  Na(g) + Cl2(g) R(2       "   P 0yVL j Na(g) + Cl(g) B(2     <    1 P 0@y /I Na+(g) + Cl(g) `(2        <    R P 0̺yk` $Na+(g) + Cl (g) n 2          <    dB P@ <Do  P 0hy\e  dCALCULATING THE LATTICE ENTHALPY Apply Hess s Law,3 2"fdB P <D)@0A P 0Pp@ 0 0dB P@ <D)@X@ P 0X0@ 0 02  P 0yy 4 712 !P 0|yE< 762 "P 0y4 752 #P 0yS< 742 $P 0hya< 732 %P 0y< 72< &P 0Xy[e   = - - - - + The minus shows you are going in the opposite direction to the definition = - (-364) - (+500) - (+121) - (+108) + (-411) = - 776 kJ mol-1 OR& Ignore the signs and just use the values; If you go up you add, if you come down you subtract the value = - - - - = (364) - (500) - (121) - (108) - (411) = - 776 kJ mol-1v 2C 2<)  l)fffff !!2 'P 0Dz &  712 (P 08z u  762 )P 0z =  752 *P 0 z   742 +P 0xz i  732 ,P 0lz   72B P s *޽h ? ̙33y___PPT10Y+D=' = @B +$ 0L0 ##*7 D#(  jB  BDo# jB   BDo  dB   <D) v dB   <D>vvvdB  <D> v dB  <D)dB  <D>/dB  <D>  jB  BDorr| jB  BDo((jB @ BDo9jjjB  BDoPP2  6z w  712  6 !z(j 762  6\za( 752  6P)z@ 742  6'zc   732  6+z   72  6P3z T rt  Mg(s) + Cl2(g) R(2          6:zU  MgCl2(s)R (2         6Az3 T r  Mg(g) + Cl2(g) R(2           6Iz$ | Mg(g) + 2Cl(g) B(2      B " 6Oz,{ (Mg2+(g) + 2Cl (g) |(2            dB # <Do:  b^B $ 6D>"("2 % 0Yz &  77  & 0]z 4i Mg+(g) + 2Cl(g) `(2          ' 0dz^ &R Mg2+(g) + 2Cl(g) T(2          ) BwzH  Enthalpy of formation of MgCl2 Mg(s) + Cl2(g)   > MgCl2(s) Enthalpy of sublimation of magnesium Mg(s)   > Mg(g) Enthalpy of atomisation of chlorine Cl2(g)   > Cl(g) x2 Ist Ionisation Energy of magnesium Mg(g)   > Mg+(g) + e 2nd Ionisation Energy of magnesium Mg+(g)   > Mg2+(g) + e Electron Affinity of chlorine Cl(g) + e   > Cl(g) x2 Lattice Enthalpy of MgCl2 Mg2+(g) + 2Cl(g)   > MgCl2(s)^@%Px&@Px%@PnPZ#@PxPn#@ PxPZ@*Pn@#Pxfff   $f#f "f  "f   f fff   t        I 2 * 6 z! E1(  2 + 6}z![ E2(  2 , 6nz!3 E3(  2 - 6Llz!# E4(  2 . 6z !  E5(  2 / 6zp !  E7(  2 0 0Dzr !  E6(   1 <zb Born-Haber Cycle - MgCl2L 2 dB 2 <D)@0A 3 0Pp@ 0 0dB 4@ <D)@X@ 5 0X0@ 0 0B  s *޽h ? ̙33y___PPT10Y+D=' = @B + 0L0 `@(   X @ @ 00z xBORN-HABER CYCLES THE ENDB(26f<f fJ @ C "A KTRE: . @ <̙? x @ 0 0 @ <̙? x @ 0 0 @ 0Pzx m OKNOCKHARDY PUBLISHING(2 fH @ 0޽h ? ̙33y___PPT10Y+D=' = @B +r@V#OE)s @S{`p|2,iͩ x  o,0?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~    Root EntrydO)PicturesCurrent UserSummaryInformation(TPowerPoint Document(DocumentSummaryInformation8