32 8 I ) transformations spontanes et transformations forces 1 1.1 Br2 0,01mol.L-1 . . Br2Cu . . K = 1,2.1025 . II Br Cu2+ .2.1 222 Cu Br Cu Br+ + + | |22,2.0r iCu BrQBr+ (( = = Qr,i < K . Cu2+ Br - . Qr,i = 0 K=1/K=0 . Qr = K . 2 1.2 U II ( Cu2+ +2Br -) . . : . U . . 2.2 . . Cu2+ U . Br U .33 Cu2+ :22 Cu e Cu+ + . Br :22 2 Br Br e + . ( ) :222 Cu Br Br Cu+ + +3 . lectrolyse .II ) Exemples d'lectrolyse1 1.1 U (Na++Cl-) . U0 > 3,5V . (indigo) . . . 2.1 : Cl2/Cl- O2/H2O : : Na+/ NaH2O/H2 : Cl2 . :2 ( ) ( ) 2( ) ( ) 2( )2 0 2 2l aq g aq gH Cl H HO Cl + + +2 1.2 . U0 > 3,5V . H2 O2 V(H2) = 2V(O2) . . .2.2 : S2O82- / SO42- O2/H2O : 34 H+/H2 : :2 ( ) 2( ) 2( )2 2l g gH O H O +III ) tude quantitative dlectrolyse .( )Q I tn eF FA= = : C = 0,1mol.L-1 I = 0,4A . . Vm = 24L.mol-1

F=96500C.mol-1 : : n (e-) 0 0 ni0 t x x ni 2x 2x 2222. .( ) 2 ( )2( ) . . .( )2 20, 4.1800.24( ) 0, 0892.96500mmI t I tn e x x n HF FVH I t V I tVHF V FVH LA A= = = =A A = == =

IV ) Quelques applications de l'lectrolyse :1 .2 3 .V ) . (2H+(aq) + SO2 (aq)) IIPbSO4(s) 1 )+( )-( 2 . . )-( )+( . VI ) 35 1 :6 12 6( ) 2( ) 2( ) 2 ( )6 6 6aq g g lC H O O CO H O + +2 :2( ) 2 ( ) 6 12 6( ) 2( )6 6 6g l aq gCO H O C H O O + +