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Questions tagged [transition-metals]

For questions about the characteristic physical properties, chemical reactions, etc. of d-block elements, group 3-12, or their compounds. Do not use this tag if your questions is about general properties of metals, use [metal] instead. Also see [rare-earth-elements].

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Copper Mirror Reaction

I would like to create a copper mirror on a plate of sandblasted glass. I know that a reaction exists: $$\ce{CuSO4 + N2H2 -> Cu + N2 + H2SO4}$$ I know that such a plate of copper is very weak. ...
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20 views

What are Technetium's physical stress characteristics?

I've looked at periodic and data tables from several sources, but none give mechanical / engineering property data on Technetium. Why is this?
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Ligand exchange/substitution [on hold]

When ligand substitution reaction will occur with no change in either the coordination number and in the charge on the complex ion? for example, in the case co2+ with ligands H2O, NH3, Cl, C2O4 or ...
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27 views

Can hexavalent chromium be created by exposure of chromium alloys to air at room temperature?

I believe that Cr on its own (as in chrome coating) oxidizes as Cr(III) when exposed to air, and similarly I think that it is the same for Cr as a component of stainless steel. Is it always the case ...
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1answer
52 views

Why does ligand substitution occur when OH- is a better ligand than NH3?

$$\ce{[Cr(H2O)3(OH)3](s) + 6NH3 -> [Cr(NH3)6]^3+ + 3H2O + 3OH-}$$ When excess $\ce{NH3}$ is added to triaquatrihydroxychromium(III), why does ligand substitution occur when $\ce{OH-}$ is a better ...
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2answers
49 views

How to balance this redox reaction taking place in a basic medium?

How to balance this reaction which is taking place in a basic medium? $$\ce{Al + MnO4- -> MnO2 + Al(OH)4-}$$ My Attempt Reduction half reaction: $$ \begin{align} \ce{4 H+ + MnO4- + 3 e- &-&...
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1answer
53 views

Density of D-block elements

Something that confuses me slightly is the trends in density when comparing periods 4, 5, and 6 in the d-block. Looking at periods 5 and 6, the density peaks at group 8, with Ruthenium and Osmium ...
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15 views

Ionization enthalpies of Transition elements

“There is generally expected increasing trend in the values as the effective nuclear charge increases. However the value[First ionisation enthalpy] of Cr is lower because of the absence of regarding ...
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What is a major product of this trans effect reaction?

In the association substitution of ligand into a complex, there is trans effect which describes where incoming ligand replaces leaving ligand. Most of examples in textbooks showed only 2 steps of ...
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34 views

Dilute FeCl3 colour is darker at 5e-4M than at 5e-3M. Why?

I did two different dilutions of $\ce{FeCl3}$ (within a $\pu{1h}$ timespan) from $\pu{0.05 M}$, and the one with $\pu{5E-4 M}$ concentration looked a darker orange than the one with $\pu{5E-3 M}$. ...
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1answer
59 views

Oxidation state in transition metals

Why does scandium has +2 oxidation state unstable? It only has +3 oxidation state stable. Scandium has outermost electronic configuration as 3d¹4s². Why it does not lose two 4s e- only instead of all ...
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1answer
85 views

Stability of 3d metal fluorides and iodides in different oxidation states

I read that the fluorides of 3d metals in lower oxidation states, e.g. $\ce{VF2}$, $\ce{TiF2}$, and $\ce{CuF}$ are thermodynamically unstable. For example, $\ce{CuF}$ disproportionates to $\ce{Cu + ...
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Rhombohedral second-order Jahn–Teller effect in Au(II) complex?

I was recently listening to a talk about the following work[1] when the author mentioned that they explained the following. In this $\ce{Au(II)}$-porphyrin complex you observe two sets of $\ce{Au-N}$ ...
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129 views

Molecular orbital diagram for terminal metal-oxo complex with dative bonds

I am interested in terminal metal-oxo complexes and their electronic structure, specifically those with coordination numbers of 6, including the oxo ligand. I know that Fe(IV)-oxo complexes tend to ...
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1answer
43 views

precipitation reaction - cellulose in schweizer reagent reacts with acid

In the regeneration of dissolved cellulose (in a cuprammonium solution) in an acid bath, say sulphuric acid, what is the chemical reaction? There is a lot about the chemistry of the production of the ...
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27 views

Breakdown of LaPorte Rule in tetrahedral transition metal complexes

What is the percentage of d-p mixing in tetrahderal complexes? Is there a way to figure out the exact wavefunctions of different orbitals of a transition metal ion in a transition metal compound?
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1answer
112 views

Which karat gold is harder, 24 kt or 18 kt?

$\pu{24 kt}$ gold indicates that $24/24$ part of it, i.e. $100\%$ of it is gold. $\pu{18 kt}$ indicates that $18/24$ part of it is gold. As gold is a soft element, I reckoned that $\pu{18 kt}$ gold ...
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1answer
285 views

Considering the d-d transition how, does tetracyanidonickelate(II) ion exist as a colored complex?

As I refer on google, the resources indicated that, the d block elements which have unpaired electrons as in their ions, when they are making complexes with ligands, they can absorb different ...
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2answers
62 views

Transition metal or transition element?

With reference to the periodic table’s d-block, are the terms “transition metals” and “transition elements” interchangeable when describing these elements? Are there any situations where it would be ...
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247 views

Why do NON -Transition elements exhibit variable oxidation state?

I know transition elements exhibit variable oxidation states because valence electrons are in d block and s which are very close so they have similar energies ,thus with slightly different energies ...
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304 views

Compare stability of transition metal cations in aqueous solution

I have to compare the stability of the following transition metal cations: $\ce{Co^3+, Fe^3+, Cr^3+, Sc^3+}$ in aqueous solution. (Source: Joint Entrance Exam (JEE) 2013 Mains India) The first thing ...
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1answer
245 views

Does tetraoxidovanadium (VO4+) ion exist?

In my book (NCERT India), it is mentioned that: (page 224) ...$\ce{Mn2O7}$ gives $\ce{HMnO4}$ and $\ce{CrO3}$ gives $\ce{H2CrO4}$ and $\ce{H2Cr2O7}$. $\ce{V2O5}$ is, however, amphoteric though ...
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1answer
471 views

Colour of the transition metal complexes [closed]

I read in my Chemistry AP class that the colour of the transition metal complexes is due to the wavelength of the visible light that is left unabsorbed, when the d subshell is split due to the ...
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1answer
143 views

ligand pi system irreducible representation for trigonal bipyramidal transition metal complex

I am considering a D$_{3h}$ trigonal bipyramidal transition metal complex MX$_5$. I have found that the irreducible representation for the ligand s and $\sigma$ systems is 2A$_1'$+A$_2''$+E$'$. I ...
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233 views

Meaning of - “Redox Potential of Vanadium 2+/3+ Has Low Value”

This site mentions: The lower value for Vanadium is due to the stability of $\ce{V^2+}$ as it has a half-filled $t_{2g}$ level If $\ce{M^3+}/\ce{M^2+}$ is low, it means $\ce{M^3+}$ is more stable ...
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1answer
58 views

What are the magnetic properties of [Ni(S2C2Ph2)2]^z's 3 oxidation states?

I was doing some research on Wikipedia and I came across the article on non-innocent ligands. It talked about the chemical $$[\ce{Ni(S_2C_2Ph_2)_2}]^z$$ as an example. It mentioned that the transition ...
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81 views

Color of potassium permanganate and potassium dichromate [duplicate]

In $\ce{KMnO4}$, the Oxidation state of $\ce{Mn}$ is +7, which results in an electronic configuration as $\ce{[Ar] 4s^0 3d^0}$ In $\ce{K2Cr2O7}$,the Oxidation state of $\ce{Cr}$ is +6, which results ...
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484 views

The irregular trend in ionization enthalpy of 3d elements

The d block elements display several exceptional behaviours, and one of them is the irregular trend in ionization enthalpy of 3d elements. The reason given by my textbook is very confusing, which I'...
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1answer
159 views

Can we classify all the d-block elements as transition metals?

I thought that properties of d-block elements are transitional between those of s-block and p-block elements, and that is the reason for calling them transition metal. My textbook says that not all d ...
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42 views

Assignment of the NMR of a copper-oxo complex

The 1H NMR of [Cu4OCl10][Me4N]4 in DMSO has the following peaks: 3.31 ppm, medium sized 3.19 ppm, large 2.50 ppm, solvent 1.018 ppm (bump, likely just noise) Why are there two proton environments?...
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What's the difference of the emission characteristics of pyrometallurgy and hydrometallurgy processes

I have learned about that pyrometallurgy and hydrometallurgy processes are two major method to refine the metal ores for industrial applications. For some reason, I want to compare the different ...
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1answer
75 views

Is it absolutely necessary to use centrifuge to separate ethylene glycol from precipitate?

I've been trying to synthesize intermetallics of $\ce{XY}$ type using transition metal salts and main group element salts. For my system, EG, DEG, and TEG are good solvents. However, because of them ...
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Chemistry d block [duplicate]

In, transition metals, they show coloured compounds Why do some of them do not show any colour. Why ti3+ shows colour as it does not have any electron in d orbital and what is zn2+ colorless
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1answer
47 views

Thermal oxidation of gold(I) sulfide

As far as I know the chemistry of $\ce{Ag}$ and $\ce{Au}$ are almost the same; because $\ce{Ag}$ belongs to the 4d series and $\ce{Au}$ belongs to the 5d series, we know the size of 4d and 5d are ...
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286 views

Why do transition metals make colored compounds despite the remaining d orbitals being hybridized? [closed]

I know that transition metals make colored compounds when they forms a bond with a ligand, as the ligand increases the energy level of $\ce{d_{x^2-y^2}}$ and $\ce{d_{z^2}}$ orbital by repelling these ...
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2answers
225 views

Does titanium(II) oxide conduct electricity? [duplicate]

In my book, it is given that $\ce{TiO(s)}$ is an electrical conductor. But I'd think that since $\ce{TiO(s)}$ is ionic and in solid state, it shouldn't conduct electricity. So, why does it conduct ...
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1answer
200 views

Why does cobalt have no negative charge?

I would like to know why cobalt cannot have a negative charge (or at least why a negative charge for cobalt isn't typical). I am not sure where I have gone wrong in my reasoning. The electronic ...
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1answer
66 views

Is it possible to dissolve gold in zinc?

I know you can dissolve gold in mercury, but i do not have access to any. Would it be possible to dissolve it in molten zinc instead mercury.
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506 views

Why does cobalt primarily form low-spin complexes?

Why is $\ce{[Co(NH3)6]^3+}$ a low spin complex while the nickel equivalent is a high spin complex? And in general, why does cobalt have a tendency to form these low spin complexes? In "Why is ...
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75 views

How to rationalize the colour change of the thermochromic bis(diethyl-ammonium) tetrachloridocuprate(II) complex

The colour of the compound changes from deep green/green-blue to yellow upon raising the temperature. I'm trying to rationalise this by using the d-orbital splitting, but I've got myself in a logic ...
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1answer
263 views

Hydrolysis of transition metals' halides?

So, it's a relatively common known solubility rule that any hydroxide with a cation not in the first two groups is basically insoluble. So supposing we have a transition or post-transition metal $M$ ...
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134 views

How does the hexaaquacopper (II) form? [duplicate]

So the hexaaquacopper (II) ion has an octahedral structure with 6 aqua ligands datively bonded to the central Cu2+ cation: My question is: how is this possible if the electronic configuration of the ...
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92 views

Reversed trends in stability of transition metal ions with respect to oxidation state

Why is titanium more stable with a lower oxidation state, but vanadium more stable with a larger oxidation state? More specifically, why is $\ce{Ti^{+}}$ more stable than $\ce{Ti^{3+}}$, but $\ce{V^{...
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167 views

Why Mn atom show maximum valency of 4 with F atom?

Mn ($3d^5$, $4s^2$) can have maximum 7 unpaired electrons in excited state so it should have formed MnF7 molecule but it can form only MnF4 molecule. Is it because: $d_{xy}, d_{yz}, d_{zx}$ orbitals ...
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68 views

Why is the Mn(II)/Mn(0) standard reduction potential exceptionally low?

Why does $\ce{Mn^{+2}/Mn}$ have an exceptionally low $\pu{E^o}$ value? Is it because of the lesser delocalization of electrons, or the stable $\ce{Mn^{+2}}$ showing a resistance to change? Does it ...
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2answers
94 views

Why does it yield iron(II) chloride instead of iron when copper meets iron(III) chloride? [closed]

Complete the equation: $$\ce{Cu + FeCl3 -> ? + ?}$$ I wrote $\ce{CuCl2}$ and $\ce{Fe}$, but it turned out to be $\ce{Cu}$ and $\ce{FeCl2}$. I really wonder why.
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960 views

reduction of Fe3+ to Fe2+ in (slightly) oxidated FeCl2 solution

I am doing some experiments with Fe2+ to create nano crystals (in aqueous solution) but Fe3+ is messing with my experiment. I was planning to use some Zinc (which I'll need to order from VWR or Sigma) ...
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321 views

Why does Zinc not have magnetic properties despite it being a transition element?

I know Zinc has a full d-orbital which might contribute to the effect. But it is not ferromagnetic or paramagnetic like other transition element complexes. Why is that?
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Trend in the infrared stretching of molecular hydrogen to group 8 transitions metals?

While going through old notes, in relation to the Dewar-Chatt-Duncanson model, it states that the stretching frequency for $\ce{N2}$ to the group 8 transition metals ($\nu(\ce{NN})$) proceeds as: \...
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204 views

electron counting for transition metal-oxo ligand compound

Using donor-pair method, how many electrons would an oxo ($O^{2-}$) ligand contribute? I cannot decide if it is 2 or 4.