2 Cr MoW2-1通性2-2Cr及其化合物2-3Mo和W13
13 2 Cr Mo W 2-1 通性 2-2 Cr 及其化合物 2-3 Mo 和 W
2-1通性氧-还反应Cr[Arj3d54s118pm+6 +3 +2Mo[Kr]4d55s]130pm同多酸/杂多酸+6+5+4+3W [Xe]4f145d*6s2 130pmCr,Mo和W具有最高的熔、沸点。14
14 2-1 通性 Cr [Ar]3d 54s 1 118pm +6 +3 +2 氧-还反应 Mo [Kr]4d 55s 1 130pm +6 +5 +4 +3 同多酸 / 杂多酸 W [Xe]4f 145d 46s 2 130pm Cr, Mo和 W 具有最高的熔、沸点
Note that whereas Cr and Mo havea d5sl configuration, W is d+s2 duetothe intervention of the lanthanons between the 6s and 5d element.As aresult of this lanthanide effect, the energy difference between 6s and5dorbitals increases to more than the extra stability of the half-filled d5slconfiguration15
15 Note that whereas Cr and Mo have a d 5 s 1 configuration, W is d 4 s 2 due to the intervention of the lanthanons between the 6s and 5d element. As a result of this lanthanide effect, the energy difference between 6s and 5d orbitals increases to more than the extra stability of the half-filled d 5 s 1 configuration
In fact,exceptfor stoichiometric similaritiesin the same oxidation statesthe 4d and5delements arequitedifferentfromthe3delement.还原剂Cr(VI) → Cr() ,Cr(II)强还原剂，例如ZnSnSnClMo(VI)Mo(V),Mo(IV)-Mo(Ill)W(VI)Mo(VI）和W(VI)的酸性溶液中，易形成同核多酸或异多酸；Cr(VI），只有CrO2、Cr,O,2-，无异多酸16
16 Mo(Ⅵ) 和 W(Ⅵ)的酸性溶液中，易形成同核多酸或异多酸； Cr(Ⅵ)，只有CrO4 2-、Cr2O7 2-，无异多酸. 还原剂 Cr(Ⅵ) → Cr(III) , Cr(Ⅱ) 强还原剂，例如 Zn Sn SnCl2 Mo(Ⅵ) → Mo(Ⅴ), Mo(Ⅳ)→ Mo(III) W(Ⅵ) In fact，except for stoichiometric similarities in the same oxidation states，the 4d and 5d elements are quite differentfrom the 3d element
2-2Cr及其化合物电子构型：Cr[Ar|3d54s氧化数：+6+3+2的元素电势图如下：1.36Cr3+ =0. 407Cr2+ =0.913R/V:CrzOF-Cr0.744-0.13-1.114pR/V:CrOr-Cr(OH)3Cr(OH)2Cr17
17 2-2 Cr 及其化合物 电子构型：Cr [Ar]3d 54s 1 氧化数: +6 +3 +2