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transition metal chemistry of manganese complexes oxidation states +2 +3 +4 +6 +7 redox chemical reactions physical properties advanced inorganic chemistry of manganese

Revision: 3d block Transition Metals chemistry of manganese

Periodic Table - Transition Metals - 3d block Manganese Chemistry - Doc Brown's Chemistry  Revising Advanced Level Inorganic Chemistry Periodic Table Revision Notes

Part 10 Transition Metals 3d–block:  

10.7 Manganese Chemistry

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All my periodic table (3d-block) advanced level chemistry revision study notes

All my advanced A level inorganic chemistry revision study notes

GCSE Level Notes on Transition Metals (for the basics)

Sub-index for this page

(a) introduction to the chemistry of manganese and data tables

(b) manganese(II) chemistry

(c) manganese(III) chemistry

(d) manganese(IV) chemistry

(e) manganese(VI) chemistry

(f) manganese(VII) chemistry

10.7. (a) Chemistry of Manganese Mn, Z=25, 1s22s22p63s23p63d54s2

Manganese exhibits oxidation states of +2, +3, +4, +6 and +7, though the chemistry you will most likely encounter is that of Mn2+ (+2) salts and complex ions, manganese(IV) oxide, MnO2 (+4) and the useful oxidising agent (potassium) manganate(VII) ion MnO4 (+7).

This page describes the chemistry of the principal oxidation states of manganese, redox reactions of manganese, ligand substitution displacement reactions of manganese, balanced equations of manganese chemistry, formula of manganese complex ions, shapes and colours of manganese complexes, formula of compounds

See also the absorption spectra and colours of manganese compounds   *   [WEBSITE SEARCH BOX]

data comparison of manganese with the other members of the 3d–block and transition metals

Z and symbol 21 Sc 22 Ti 23 V 24 Cr 25 Mn 26 Fe 27 Co 28 Ni 29 Cu 30 Zn
property\name scandium titanium vanadium chromium manganese iron cobalt nickel copper zinc
melting point/oC 1541 1668 1910 1857 1246 1538 1495 1455 1083 420
density/gcm–3 2.99 4.54 6.11 7.19 7.33 7.87 8.90 8.90 8.92 7.13
atomic radius/pm 161 145 132 125 124 124 125 125 128 133
M2+ ionic radius/pm na 90 88 84 80 76 74 72 69 74
M3+ ionic radius/pm 81 76 74 69 66 64 63 62 na na
common oxidation states +3 only +2,3,4 +2,3,4,5 +2,3,6 +2,3,4,6,7 +2,3,6 +2,3 +2,+3 +1,2 +2 only
outer electron config.[Ar]... 3d14s2 3d24s2 3d34s2 3d54s1 3d54s2 3d64s2 3d74s2 3d84s2 3d104s1 3d104s2
Elect. pot. M(s)/M2+(aq) na –1.63V –1.18V –0.90V –1.18V –0.44V –0.28V –0.26V +0.34V –0.76V
Elect. pot. M(s)/M3+(aq) –2.03V –1.21V –0.85V –0.74V –0.28V –0.04V +0.40 na na na
Elect. pot. M2+(aq)/M3+(aq) na –0.37V –0.26V –0.42V +1.52V +0.77V +1.87V na na na

Elect. pot. = standard electrode potential data for manganese (EØ at 298K/25oC, 101kPa/1 atm.)

na = data not applicable to manganese

Extended data table for MANGANESE

property of manganese/unit value for Mn
Mn melting point/oC 1246
Mn boiling point/oC 1962
Mn density/gcm–3 7.33
1st Ionisation Energy/kJmol–1 717
2nd IE/kJmol–1 1509
3rd IE/kJmol–1 3248
4th IE/kJmol–1 4940
5th IE/kJmol–1 6990
atomic radius Mn/pm 124
Mn2+ ionic radius/pm 80
Relative polarising power Mn2+ ion 2.5
Mn3+ ionic radius/pm 66
Relative polarising power Mn3+ ion 4.5
Mn4+ ionic radius/pm 54
Relative polarising power Mn4+ ion 7.4
oxidation states of Mn, less common/stable +2, +3, +4, +6, +7
simple electron configuration of Mn 2,8,13,2
outer electrons of Mn [beyond argon core] [Ar]3d54s2
Electrode potential Mn(s)/Mn2+(aq) –1.18V
Electrode potential Mn(s)/Mn3+(aq) –0.28V
Electrode potential Mn2+(aq)/Mn3+(aq) +1.52V
Electronegativity of Mn 1.55


  • Uses of MANGANESE

    • Manganese is a hard brittle metal but is a most important metal in steels making tough and hard wearing manganese steel alloys e.g. for use as rock drills and railway points.

    • Ferromanganese (80% Mn, 20% Fe) is commonly used in such alloys.

    • Several compounds of manganese are used in the laboratory and manufactured products as oxidising agents.

      • Potassium manganate(VII), KMnO4, is used as a volumetric agent in redox analysis titrations.

      • Manganese(IV) oxide, MnO2, is used in zinc–carbon batteries (oxidises hydrogen to water).

    • Manganese(IV) oxide, MnO2, is also used in paints dyes.

    • Manganese compounds are found in fertilisers, fungicides and herbicides.

  • Biological role of manganese

    • Manganese is an essential trace element.

    • Manganese activates the enzyme alkaline phosphatase in bone formation and the enzyme organase in urea formation.

    • Manganese deficiency can cause deformation of the skeleton and sterility.

    • In plants manganese ions activate carboxylases.

Pd s block d blocks (3d block manganese) and f blocks of metallic elements p block elements
Gp1 Gp2 Gp3/13 Gp4/14


2 3Li 4Be Part of the modern Periodic Table of Elements: ZSymbol, z = atomic or proton number

Sc to Zn are now considered the head-top elements of groups 3 to 12

3d block of metallic elements: Scandium to Zinc focus on manganese

5B 6C
3 11Na 12Mg 13Al 14Si
4 19K 20Ca 21Sc







 [Ar] 3d34s2



[Ar] 3d54s1



   [Ar]   3d54s2



[Ar] 3d64s2



[Ar] 3d74s2



[Ar] 3d84s2



[Ar] 3d104s1



[Ar] 3d104s2


31Ga 32Ge
5 37Rb 38Sr 39Y 40Zr 41Nb 42Mo 43Tc 44Ru 45Rh 46Pd 47Ag 48Cd 49In 50Sn
6 55Cs 56Ba 57,58-71 72Hf 73Ta 74W 75Re 76Os 77Ir 78Pt 79Au 80Hg 81Tl 82Pb
7 87Fr 88Ra 89,90-103 104Rf 105Db 106Sg 107Bh 108Hs 109Mt 110Ds 111Rg 112Cn 113Nh 114Fl

Summary of oxidation states of the 3d block metals (least important) Ti to Cu are true transition metals

Sc Ti V Cr Mn Fe Co Ni Cu Zn
  (+2) (+2) (+2) +2  (3d5) +2 +2 +2 +2 +2
+3 +3 +3 +3 (+3)  (3d4) +3 +3 (+3) (+3)  
  +4 +4   +4  (3d3)     (+4)    
      +6 (+6)  (3d1) (+6)        
        +7  (3d0)          
3d14s2 3d24s2 3d34s2 3d54s1 3d54s2 3d64s2 3d74s2 3d84s2 3d104s1 3d104s2
The outer electron configurations beyond [Ar] and the (ground state of the simple atom)

Note that when 3d block elements form ions, the 4s electrons are 'lost' first.

The oxidation states and electron configuration of manganese in the context of the 3d block of elements

electrode potential chart diagram for the oxidation states of manganese ions 0 +2 +3 +7

The electrode potential chart highlights the values for various oxidation states of manganese +2 +3 +7.

Manganese oxidations states of +4 and +6 are also mentioned in the text below.

The electrode potentials involving manganese ions correspond to hydrated complex ions where the ligands are water, oxide or hydroxide.

As you can see from the chart, changing either the ligand or the oxidation state, will also change the electrode potential for that half-reaction involving a manganese ion.

The manganate(VII) ion is a powerful oxidising agent.

A quick illustration of manganese oxidation states

I came across an experiment on twitter (@mrspotassium) where you stir an acidified potassium manganate(VII) solution (in a beaker of conical flask) with sugary lollipop - mainly glucose sugar.

Alternatively, you can stir the solution with a magnetic stirrer and carefully suspend the lollipop into the potassium manganate(VII) solution - you can dip the lollipop to a greater or lesser depth to control the rate of reaction (a surface area rate factor!).

Glucose is a reducing agent and the following reduction sequence occurs.

Quite clever, the hard sugary lollipop only dissolves slowly, slowing down the reactions so that you can see a series of colour changes corresponding to the change in oxidation state of manganese.

 purple Mn(VII) => green Mn(VI) => ? Mn(IV) => violet Mn(III) => pale pink Mn(II)

Not sure on the Mn(IV) colour, apart from insoluble black solid MnO2, not sure if it can be stabilised in solution? possibly with a suitable ligand?

More details via the sub-index for this page.

(b) Manganese(II) oxidation state chemistry

  • pale pink octahedral shape complex hexaaquamanganese(II) ion [Mn(H2O)6]2+ Mn oxidation state +2The reactions of the manganese(II) ion:

    • Electron configuration of Mn2+ is [Ar]3d5

    • An aqueous solution of manganese(II) sulfate MnSO4(aq) or manganese(II) chloride MnCl2(aq) will do for most laboratory experiments investigating the chemistry of the manganese(II) state.

    • Manganese(II) salts are readily made by dissolving the carbonate, MnCO3, in the appropriate dilute acid.

      • e.g. MnCO3(s) + 2HCl(aq) ===> MnCl2(aq) + H2O(l) + CO2(g)

      • H2SO4 for the sulfate, MnSO4,  and 2HNO3 for the nitrate, Mn(NO3)2.

      • The very pale pink hexaaquamanganese(II) [Mn(H2O)6]2+ is quite 'redox' stable in aqueous solution with respect to dissolved oxygen from air.

    • From manganese(II) solutions, the alkalis sodium hydroxide or ammonia, produce the hydrated manganese(II) hydroxide precipitate. There is no further reaction with excess of either alkali.

      • Mn2+(aq) + 2OH(aq) ===> Mn(OH)2(s) 

      • (can be written as the neutral complex [Mn(OH)2(H2O)4]0

      • the hydroxide is almost white if oxygen is excluded, but it gradually turns brown to form hydrated manganese(III) oxide.

      • then 4Mn(OH)2(s)  + O2(g) ===> 2Mn2O3(s)  + 4H2O(l)   

        • the hydrated oxide Mn2O3can also be written as a hydroxy–oxide, MnO(OH)

      • Mn oxidised (II)==>(III) and ==>(IV) possibly to MnO2 too?, O reduced (0)==>(–1)

      • VIEW more on ppts. with OH, NH3 and CO32–, & complexes with excess reagent

    • With manganese(II) ion solutions, alkaline aqueous sodium carbonate solutions produces a precipitate of manganese(II) carbonate.

      • Mn2+(aq) + CO32–(aq) ===> MnCO3(s) (white ppt.)

        • Like Mn(OH)2 it readily oxidises to brown Mn2O3 or black MnO2?

    • Oxidation of the manganese(II) ion

      • Acidified Mn2+ is not oxidised by hydrogen peroxide H2O2.

      • BUT alkaline Mn(OH)2 + H2O2 gives brown Mn2O3 or MnO(OH), a hydrated manganese(III) oxide/hydroxide.

      • This again illustrates how redox potentials vary with pH i.e. change in relative stability of oxidation states for the Mn3+/Mn2+ half–cell potential.

    • The hexa–aqua manganese(II) ion readily forms complexes with polydentate ligands.

    • (i) [Mn(H2O)6]2+(aq) + 3en(aq) ===> [Mn(en)3]2+(aq) + 6H2O(l)   (en = H2NCH2CH2NH2)

      • Kstab = [[Mn(en)3]2+(aq)] / [[Mn(H2O)6]2+(aq)] [en(aq)]3

      • Kstab = 5.0 x 105 mol–3 dm9 [lg(Kstab) = 5.7]

      • Remember [H2O] is not included in the equilibrium expression.

    • (ii) [Mn(H2O)6]2+(aq) + EDTA4–(aq) ===> [Mn(EDTA)]2–(aq) + 6H2O(l)

      • Kstab = [[Mn(EDTA)3]2–(aq)] / [[Mn(H2O)6]2+(aq)] [EDTA4–(aq)]

      • Kstab = 1.0 x 1014 mol–1 dm3 [lg(Kstab) = 14.0]

    • The higher Kstab value for EDTA reflects the greater entropy change. A simplistic, but not illegitimate argument, shows that in (i) a net gain of 3 particles, but in (ii) 5 more particles are formed.

  • The electrode potential chart highlights the values for various oxidation states of manganese.

  • Summary of some complexes–compounds & oxidation states of manganese compared to other 3d–block elements

(c) Manganese(III) oxidation state chemistry

  • octahedral shape violet complex hexaaquamanganese(III) ion [Mn(H2O)6]3+ Mn oxidation state +3The chemistry of the manganese(III) ion

    • Electron configuration of Mn3+ is [Ar]3d4

    • The violet Mn(H2O)6]3+(aq) ion is unstable in aqueous solution, hence little reference to its reactions.

    • Give the two half-reaction Eø data:

    • (i) Mn3+(aq)  +  e-  ===>  Mn2+(aq)      (Eø = +1.56V, so the manganese(III) ion is powerful oxidising agent)

    • (ii) O2(g)  +  4H+(aq)  +  4e-  ===>  2H2O(l)   (Eø = +1.23V, so is oxygen, but not as powerful as Mn3+(aq))

    • So the Mn3+(aq) ion will oxidise water to oxygen and be reduced to the +2 oxidation state - argument presented below.

    • (iii) 4Mn3+(aq)  +  2H2O(l)    ===>  4Mn2+(aq)  +  O2(g)  +  4H+(aq)

    • To prove thermodynamic feasibility: Eøreaction = Eø(red) - Eø(ox) = (+1.56) - (+1.23) = 0.33V

    • Note how to balance equation (iii):

    • You add 4 x (i) to the reverse of equation (ii), a 4 electron change or 4 'units' of oxidation state to rise and fall,

    • the oxidation state decrease is (i) 4 Mn(+3) to 4 Mn(+2) and oxidation state increase (ii) 2O(-2) to 2O(0).

(d) Manganese(IV) oxidation state chemistry

  • The chemistry of manganese(IV) in terms of manganese (IV) oxide

    • The only important manganese(IV) compound is the solid black oxide, MnO2.

    • Manganese(IV) oxide is an excellent catalyst for the decomposition of hydrogen peroxide which is a useful way of making oxygen for school laboratory experiments. (See Gas Preparations)

      • 2H2O2(aq) ===> 2H2O(l) + O2(g)

    • If a small quantity of manganese(IV) oxide is added to ice–cooled concentrated hydrochloric acid an anionic octahedral manganese(IV) chloro complex ion is formed.

      • If the mixture is filtered through glass wool the brown colour of the complex can be seen.

      • (i) MnO2(s) + 4H+(aq) + 6Cl(aq) ===> [MnCl6]2–(aq) + 2H2O(l)

      • The hexachloromanganate(VI) complex ion has an octahedral shape and co-ordination number of 6.

      • The overall charge on this manganese complex ion is 2- (+4 - 6x-1).

      • If the mixture is warmed, chlorine is formed as the complex decomposes to Mn(II) compounds.

      • (ii) [MnCl6]2–(aq) ==> MnCl2(aq) + 2Cl(aq) + Cl2(g)

      • The overall equation is

      • (iii) MnO2(s) + 4H+(aq) + 4Cl(aq) ===> MnCl2(aq) + Cl2(g) + 2H2O(l)

      • So manganese(IV) oxide is acting as an oxidising agent i.e. the chloride ion is oxidised to chlorine.

      • Oxidation state changes: Mn from +4 to +2 (reduction) and Cl from -1 to 0 (oxidation).

(e) The chemistry of manganese(VI) oxidation state

  • tetrahedral shaped dark green manganate(VI) ion [MnO4]2- Mn oxidation state +6A solution of the tetrahedral (O-Mn-O bond angle 109.5o) dark green manganate(VI) ion, MnO42– can be made by strongly heating a mixture of manganese(IV) oxide, potassium hydroxide and potassium chlorate(V) in a crucible and extracting the manganese(VI) compound with water.

  • However, the manganate(VI) ion, MnO42– is unstable, especially in acid solution, and slowly undergoes disproportionation – i.e. a species in one oxidation state spontaneously and simultaneously changes into two species of different oxidation states – one higher and one lower in oxidation number. Adding dil. sulfuric acid to the crucible fusion extract will hasten the process.

  • The green solution of the manganate(VI) ion changes to the purple manganate(VII) ion and a black precipitate of manganese(IV) oxide is formed.

  • 3MnO42–(aq) + 4H+(aq) ===> 2MnO4(aq) + MnO2(s) + 2H2O(l)

  • The equilibrium constant for the reaction, K, is ~1058, so there ain't much chance of the green colour hanging around after acidification!

  • The oxidation state changes are 3Mn(+6) ===> 2Mn(+7) + Mn(+4)

    • a total '18 units worth' of redox change, always check your oxidation number balancing before anything else! The oxidation states of H and O remain at +1 and –2 respectively.

  • The obviously feasible and spontaneous disproportionation reaction can be explained by considering the standard electrode potentials (standard reduction potential) involved (quoted as half–cell reductions, as is the convention).

    • (i) MnO4(aq) + e ===> MnO42–(aq)  (EØ = +0.56V)

    • (ii) MnO42–(aq) + 4H+(aq) + 2e  ===> MnO2(s) + 2H2O(l)  (EØ = +1.70V, in acid solution)

    • (ii) has the more positive potential, so this will be the reduction half–cell reaction.

    • (i) has the less positive potential, so this will be (reversed) the oxidation half–cell reaction.

    • EØreaction = EØreduction – EØoxidation = (+1.70) – (0.56) = +1.14V, well over 0V, therefore very feasible!

    • Incidentally:

    • Given the two half–cell reactions, you get the complete balanced equation by adding (ii) plus 2 x (i) reversed.

    • The greater stability of the manganate(VI) ion in alkali can also be explained by considering the electrode potential for (ii) in an alkaline media.

    • (iii)  MnO42–(aq) + 2H2O(l) + 2e  ===> MnO2(s) + 4OH(aq)  (EØ = +0.59V, in alkaline solution)

    • so, re–calculating gives

    • EØreaction = EØreduction – EØoxidation = (+0.59) – (0.56) = +0.03V, just over 0, therefore just feasible! but on the basis of an equilibrium argument, here, the far lower EØreaction, suggests the MnO42– ion is far more likely to exist, i.e. more stable, in a very high pH solution and in practice it is stable for a few hours in alkali.

    • This is a good example of how change in pH can affect a standard reduction potential.

    • See also copper(I) chemistry for another example of disproportionation.

(f) The chemistry of the manganese(VII) oxidation state i.e. the manganate(VII) ion

  • tetrahedral shaped purple manganate(VII) ion [MnO4]- MnO4- Mn oxidation state +7The tetrahedral deep purple manganate(VII) ion, MnO4, can be considered as an intensely coloured and very stable complex ion (except in the presence of something that is readily oxidised!).

  • Potassium manganate(VII), KMnO4 is used to titrate (i) iron(II) ions, (ii) ethanedioates, (iii) hydrogen peroxide and (iv) nitrate(III) ions (old name 'nitrite').

  • The titrations are done with dilute sulfuric acid present to prevent side reactions e.g. MnO2 formation (brown colouration or black precipitate).

  • The mineral acid must be dilute sulfuric acid because potassium manganate(VII) will oxidise hydrochloric acid (Cl ==> Cl2) and nitric(V) acid is an oxidising agent itself, so use of either of these acids leads to inaccurate false titration results.

  • The Mn2+ ions formed are almost colourless (very pale pink), so the end–point is the first permanent faint pink due to the first trace of excess of the brilliant purple manganate(VII) ion. 

  • (i) MnO4(aq) + 8H+(aq)  + 5Fe2+(aq) ===> Mn2+(aq) + 5Fe3+(aq) + 4H2O(l)

  • Theoretically, there are actually two simultaneous colour changes, both masked by the redox indicator change.

    • The purple manganate(VII) ion changes on reduction to the very pale pink manganese (II) ion,

    • and the pale green iron(II) ion changes on oxidation to the orange iron(III) ion,

    • However, in the dilute solution of the titration mixture, the first permanent pink colour does stand out from the pale orange of the iron(III) ion plus the very pale pink of the manganese(II) ion.

    • In the other examples (ii) to (iv) below, the reductants and oxidation products are colourless, so the colour of the very pale pink manganese(II) ion is visually overridden by the first drop of excess of bright purple potassium manganate(VII) at the end-point of the volumetric titration.

    • You do need excess dil. sulfuric acid in the titration and it will NOT act as an oxidising agent or a reducing agent to interfere with the quantitative and accurate volumetric redox titration.

    • e.g. acids you should NOT use for a potassium manganate(VII) redox titration:

      • conc. sulfuric acid is an oxidising agent, dilute is fine,

      • hydrochloric acid, manganate(VII) ion oxidises the chloride ion to chlorine,

      • nitric acid is an oxidising agent,

      • ethanoic acid is too weak to provide a high H+(aq) concentration and many other weak organic acids are oxidised

  • (ii) 2MnO4(aq) + 16H+(aq)  +  5C2O42–(aq) ===> 2Mn2+(aq)  +  8H2O(l) + 10CO2(g)

    • this reaction speeds up as the titration proceeds because Fe3+ acts as a catalyst, this situation is known as auto–catalysis.

  • (iii) 2MnO4(aq) + 6H+(aq)  +  5H2O2(aq) ===> 2Mn2+(aq)  +  8H2O(l)  + 5O2(g)

  • (iv) 2MnO4(aq) + 6H+(aq)  +  5NO2(aq) ===> Mn2+(aq)  +  5NO3(aq)  +  3H2O(l)

  • See also fully worked examples of redox volumetric titration calculation questions on these titrations.

  • The autocatalysis of the ethanedioate/potassium manganate (VII) titration reaction by the Mn2+ ions is described under homogeneous catalysis in Appendix 6.

  • Potassium manganate(VII), is strong enough to oxidise chloride ions. Running conc. hydrochloric acid onto the damp crystals is a handy way of making chlorine in the laboratory.

    • 2MnO4(aq) + 16H+(aq)  + 10Cl(aq) ===> 2Mn2+(aq)  + 8H2O(l) + 5Cl2(g)

    • This reaction is the reason that dilute sulfuric acid is used in potassium manganate(VII) titrations and not dil. hydrochloric acid, which would lead to inaccurate results.

The vertical connection of manganese with the other d-block elements of Group 7 (IUPAC designation)

Modern IUPAC group numbers of 3-12 Outer electron structure of d-block elements which includes the transition metals

Manganese is the head element of Group 7 plus Technetium, Rhenium and Bohrium

Their outer electron configurations are nd5(n+1)s2 (n = 3 to 6)

[e- core] Gp 3 Group 4 Group 5 Group 6 Group 7 Group 8 Group 9 Group 10 Group 11 Group 12
P'd 4, 3d block [Ar] core 21Sc




















P'd 5, 4d block (Kr] core 39Y




















P'd 6, 5d b'k  [Xe] core 57La




















P'd 7, 6d b'k [Rn] core 89Ac





















biological role of manganese, chemistry of the manganese(II) ion Mn2+, octahedral complexes of manganese(II), standard electrode potential of Mn2+, oxidation of manganese(II) to manganese(VII) with alkaline chlorine, chemistry of manganate(VII) ion MnO4 2-, chemistry of the manganate(VI) ion, hexaaquamanganese(II) ion, standard electrode potential for Mn2+ manganese(II) ion, oxidising power of manganate(VII), colours of manganese ions keywords redox reactions ligand substitution displacement redox reactions ligand substitution displacement balanced equations formula complex ions complexes ligand exchange reactions redox reactions ligands colours oxidation states manganese ions Mn(0) Mn2+ Mn(+2) Mn(II) Mn3+ Mn(+3) Mn(III) Mn4+ Mn(+4) Mn(IV) Mn(+6) Mn (VI) Mn(+7) Mn(VII): MnSO4 MnCl2 MnO2 MnO Mn2O3 MnO4– MnO42– KMnO4 Mn(OH)2 MnCO3 + 2HCl ==> MnCl2 + H2O + CO2 Mn2+ + 2OH– ==> Mn(OH)2 [Mn(OH)2(H2O)4] 4Mn(OH)2 + O2 ==> 2Mn2O3 + 4H2O  Mn2+ + CO32– ==> MnCO3 [Mn(H2O)6]2+ + 3en  ===> [Mn(en) 3]2+ + 6H2O (en = H2NCH2CH2NH2) Kstab = [[Mn(en)3]2+] / [[Mn(H2O)6]2+] [en]3 Kstab = 5.0 x 105 mol–3 dm9 [lg(Kstab) = 5.7] [Mn(H2O)6]2+ + EDTA4– ===> [Mn(EDTA)]2– + 6H2O Kstab = [[Mn(EDTA)3]2–] / [[Mn(H2O)6]2+] [EDTA4–] MnO2 + 4H+ + 6Cl– ==> [MnCl6]2– + 2H2O [MnCl6]2– ==> MnCl2 + 2Cl– + Cl2 MnO2 + 4H+ + 4Cl–  ==>MnCl2 + Cl2 + 2H2O 3MnO2 + 6OH– + ClO3– ==> 3MnO42– + 3H2O + Cl– MnO42– + 4H+ ==> 2MnO4– + MnO2 + 2H2O 3Mn(+6) ==> 2Mn(+7) + Mn(+4) MnO4– + e– ==> MnO42– (EØ = +0.56V) MnO42– + 4H+ + 2e– ==> MnO2 + 2H2O MnO42– + 2H2O + 2e– ==> MnO2 + 4OH– MnO4– + 8H+ + 5Fe2+ ==> Mn2+ + 5Fe3+ + 4H2O 2MnO4– + 16H+  + 5C2O42– ==> 2Mn2+ + 8H2O + 10CO2 2MnO4– + 6H+ + 5H2O2 ==> 2Mn2+ + 8H2O + 5O2 2MnO4– + 6H+ + 5NO2– ==> Mn2+ + 5NO3– + 3H2O 2MnO4– + 16H+ + 10Cl– ==> 2Mn2+ + 8H2O + 5Cl2 oxidation states of manganese, redox reactions of manganese, ligand substitution displacement reactions of manganese, balanced equations of manganese chemistry, formula of manganese complex ions, shapes colours of manganese complexes  Na2CO3 NaOH NH3 transition metal manganese for AQA AS chemistry, transition metal manganese for Edexcel A level AS chemistry, transition metal manganese for A level OCR AS chemistry A, transition metal manganese for OCR Salters AS chemistry B, transition metal manganese for AQA A level chemistry, transition metal manganese for A level Edexcel A level chemistry, transition metal manganese for OCR A level chemistry A, transition metal manganese for A level OCR Salters A level chemistry B transition metal manganese for US Honours grade 11 grade 12 transition metal manganese for pre-university chemistry courses pre-university A level revision notes for transition metal manganese  A level guide notes on transition metal manganese for schools colleges academies science course tutors images pictures diagrams for transition metal manganese A level chemistry revision notes on transition metal manganese for revising module topics notes to help on understanding of transition metal manganese university courses in science careers in science jobs in the industry laboratory assistant apprenticeships technical internships USA US grade 11 grade 11 AQA A level chemistry notes on transition metal manganese Edexcel A level chemistry notes on transition metal manganese for OCR A level chemistry notes WJEC A level chemistry notes on transition metal manganese CCEA/CEA A level chemistry notes on transition metal manganese for university entrance examinations physical and chemical properties of the 3d block transition metal manganese, oxidation and reduction reactions of manganese ions, outer electronic configurations of manganese, principal oxidation states of manganese, shapes of manganese's complexes, octahedral complexes of manganese, tetrahedral complexes of manganese, square planar complexes of manganese, stability data for manganese's complexes, aqueous chemistry of manganese ions, redox reactions of manganese ions, physical properties of manganese, melting point of manganese, boiling point of manganese, electronegativity of manganese, density of manganese, atomic radius of manganese, ion radius of manganese, ionic radii of manganese's ions, common oxidation states of manganese, standard electrode potential data for manganese, ionisation energies of manganese, polarising power of manganese ions, industrial applications of manganese compounds, chemical properties of manganese compounds, why are manganese complexes coloured?, isomerism in the complexes of manganese, formulae of manganese compounds, tests for manganese ions


GCSE Level Notes on Transition Metals (for the basics)

The chemistry of Scandium * Titanium * Vanadium * Chromium * Manganese

The chemistry of Iron * Cobalt * Nickel * Copper * Zinc * Silver & Platinum

Introduction 3d–block Transition Metals * Appendix 1. Hydrated salts, acidity of hexa–aqua ions * Appendix 2. Complexes & ligands * Appendix 3. Complexes and isomerism * Appendix 4. Electron configuration & colour theory * Appendix 5. Redox equations, feasibility, Eø * Appendix 6. Catalysis * Appendix 7. Redox equations * Appendix 8. Stability Constants and entropy changes * Appendix 9. Colorimetric analysis and complex ion formula * Appendix 10 3d block – extended data * Appendix 11 Some 3d–block compounds, complexes, oxidation states & electrode potentials * Appendix 12 Hydroxide complex precipitate 'pictures', formulae and equations Some pages have a matching sub-index

Advanced Level Inorganic Chemistry Periodic Table Index: Part 1 Periodic Table history Part 2 Electron configurations, spectroscopy, hydrogen spectrum, ionisation energies * Part 3 Period 1 survey H to He * Part 4 Period 2 survey Li to Ne * Part 5 Period 3 survey Na to Ar * Part 6 Period 4 survey K to Kr AND important trends down a group * Part 7 s–block Groups 1/2 Alkali Metals/Alkaline Earth Metals * Part 8  p–block Groups 3/13 to 0/18 * Part 9 Group 7/17 The Halogens * Part 10 3d block elements & Transition Metal Series * Part 11 Group & Series data & periodicity plots All 11 Parts have their own sub-indexes near the top of the pages

Group numbering and the modern periodic table

The original group numbers of the periodic table ran from group 1 alkali metals to group 0 noble gases. To account for the d block elements and their 'vertical' similarities, in the modern periodic table, groups 3 to group 0 are numbered 13 to 18. So, the p block elements are referred to as groups 13 to group 18 at a higher academic level, though the group 3 to 0 notation is still used, but usually at a lower academic level. The 3d block elements (Sc to Zn) are now considered the head (top) elements of groups 3 to 12.

Website content © Dr Phil Brown 2000+. All copyrights reserved on revision notes, images, quizzes, worksheets etc. Copying of website material is NOT permitted. Doc Brown's Chemistry theoretical-physical chemistry revision notes for pre-university level students on d-block elements including the physical and chemical properties reactions equations and trends explained for the 3d-block of transition metals series