无机化学无机化学英文PPT (28).ppt

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1、Manganese group(VIIB):Mn,Tc,Re,Bh Valence electron configuration:(n-1)d5ns2Manganese elementalThe properties of manganese：(1)White metal,hard and brittle(2)Active metal：1.182V/Mn)(Mn2-=+Mn+2H2O Mn(OH)2(s)+H2Mn+2H+(dilute)Mn2+H2(3)Reaction with oxygen,halogens and other nonmetals:(4)Interaction with

2、molten base in the presence of an oxidizer：Mn+F2 MnF4 and MnF3moltenThe presence and preparation of manganese:530AlCNeutral reductionCl2MoltenWater leachingMnO2 xH2O(pyrolusite)3MnO2+6KOH+KClO3 3K2MnO4+KCl+3H2O3MnO2 Mn3O4+O23Mn3O4+8Al 9Mn+4Al2O3Manganese compoundsThe valence electron configuration o

3、f Mn:3d54s2The oxidation number of Mn is continuous:-2 to+7.Common oxidation number:+7，+6，+4,and+2.Common compound:KMnO4,K2MnO4,MnO2,MnSO4 and MnCl2.Except MnO2,the others are easily soluble in water,and the corresponding manganese ions are:MnO4-,MnO42-,and Mn2+Oxidation state+7+6+4+2Molecular formu

4、laKMnO4K2MnO4MnO2MnSO47H2OMnCl24H2OColor and statePurplish red or nearly black crystalsDark green crystalBlack amorphous powderMeat red crystalMeat red crystalDensity/(gcm-3)2.71-5.082.092.01Melting point/the change in heatAt above 200,it breaks down into K2MnO4，MnO2，O2At 640-680,it breaks down into

5、 Mn3O4,O2,K2OAt 530,it breaks down into Mn3O4,O2At 54,it is dissolved in crystalline water,anhydrous MnSO4 is white,and the burning changes to Mn3O4It was partially hydrolyzed to form HCl at 200-230 and anhydrous MnCl2 with red flake,its melting point was 650 Solubility(g/100g H2O)6.4The solution wa

6、s diluted to 1:500,000 and the color was still visibleAt 224.7gL-1(2MKOH)m it forms a green solution,static or more water,turn mauve.Does not dissolve in water60(10）143Properties of important compounds of MnVarious ions and properties of Mn in aqueous solutionOxidation value +7 +6 +3 +2Color Burgund

7、y dark-green red reddishd electron number d0 d1 d4 d5The conditions that exist in solution:neutral pH13.5 Easy acid disproportionationManganese potential diagram:1.7001.231.510.5965-0.0514 Acidic solutionV/Alkaline solutionV/Manganese()compounds Strong oxidizingMnO4 is reduced by different acidity o

8、f solution as follows:1.51V)/MnMnO(24=+-Oxidizable speciesSO32-I-Cl-H2SFe2+Sn2+ProductSO42-I2Cl2S or SO4Fe3+Sn4+2MnO4-+SO32-+OH-(Strong)2MnO42-+SO42-+H2O InstabilityHeating(Light)acidStrong alkali4MnO4-+4H+(Micro acid)4MnO2+3O2+2H2OManganese()compoundsDisproportionation in an acidic,neutral solution

9、 K2MnO4 dark green crystal,in the form of MnO42-in strongly alkaline solution.Raw materials for preparation of manganese compounds with low oxidation number Reducing(alkaline)Strong oxidizerManganese()compounds:MnO2MnO2+4HCl(strong)Cl2+MnCl2+H2O2MnO2+2H2SO4(strong)2MnSO4+O2+2H2OManganese()compoundsM

10、n(H2O)62+Mn(OH)(H2O)5+H+=1010.6K Under alkaline conditions:Mn(OH)2 presents alkalineThe hydrolysis of Mn(H2O)62+dark brown)white)without O2 Mn2+is weakly reductiveIdentification of Mn2+is commonly used NaBiO3 in HNO3 medium,and the Mn2+amount should not be much.MnS(carneous):Dilute acid soluble sulfideMn2+H2S+2NH3=MnS(S,carneous)+2NH3MnS+2HAc=Mn2+H2S+2Ac-