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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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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1answer
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Why does density decrease across the period 4 and 5 transition metals?

I know that density decreases across period 4 because the last two elements are liquids and gases which means that their densities are less but why are the densities increasing and then decreasing ...
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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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1answer
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Why is [PdCl4]2- square planar whereas [NiCl4]2- is tetrahedral?

The molecule $\ce{[PdCl4]^2-}$ is diamagnetic, which indicates a square planar geometry as all eight d electrons are paired in the lower-energy orbitals. However, $\ce{[NiCl4]^2-}$ is also $\mathrm{d^...
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3answers
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Variation in atomic sizes in the transition elements

From left to right across a period, effective nuclear charge increases in the transition series, just like in the p block, and so atomic size decreases. Here the electrons are being added to the d ...
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2answers
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Negative potential of the oxidation of iron(II) to iron(III)

The oxidation potential which I found on the internet the following reaction $$\ce{Fe^{2+} -> Fe^{3+} + e^-}$$ is $\pu{-0.77 V}$. But how can it be negative? Negative oxidation potential means ...
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1answer
161 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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1answer
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What is the electronic configuration of Cr (+1) ion

I believe it should be $\ce{d^5}$ , but i found out that it is $\ce{d^4s^1}$. Is it so? I have not found any explanation for the following. So why the strange configuration?
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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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What is the most common oxidation state of gold?

I had a test this morning which had the following question: What is the most common oxidation state for gold? (a) +1 (b) -1 (c) +2 (d) +3 Since the electronic configuration of $\ce{Au}$ is $\...
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Why do isomeric bis-ethylenediamine cobalt complexes react differently?

A compound $\ce{Co(en)2(NO2)2Cl}$ has been prepared in a number of isomeric forms.One form undergoes no reaction with $\ce{AgNO3}$ or $\ce{(en)}$ and is optically inactive. A second form reacts with $...
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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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1answer
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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.
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Reduction potential of a complex

I am given the reduction potential of $\ce{Fe^{3+}}$ to $\ce{Fe^{2+}}$ as well as the dissociation constants $\ce{K_D}$ for a $\ce{Fe^{3+}}$ complex and a $\ce{Fe^{2+}}$ complex (effectively, the ...
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Why does iron have an abnormally high ionization energy?

Along a period the ionization energy should increase because the atomic number is increasing, but there is negligible increase in shielding. However, $\mathrm{IE}_\ce{Mn} < \mathrm{IE}_\ce{Fe} > ...
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Cytotoxicity of Ru-complexes

I have a basic question: why are Ru(II)-complexes cytotoxic? What I know is that depending on the used ligand some of them interact with the DNA either via DNA-pi-stacking (intercalation) or binding ...
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2answers
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In Crystal Field Theory what does Δo=10Dq mean?

While studying the Crystal Field Theory I was told $\mathrm{Dq}$ is a unit, related to the unit $\Delta_{\mathrm{O}}$ by the relation $\Delta_{\mathrm{O}} = 10\ \mathrm{Dq}$. But aren't $\Delta_{\...
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Why is the copper in my pan magnetic?

My Momma bought a copper pan made for induction because it was the only one she could find that she wanted and was big enough to pan fry half a chicken. But I noticed something odd about the copper. ...
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1answer
24k views

Why does potassium permanganate turn colourless when reacted with sulfur dioxide?

I learnt at school that when sulfur dioxide gas, $\ce{SO2}$, is combined with potassium permanganate, $\ce{KMnO4}$, the purple solution will become colourless. What happens in the solution to cause ...
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4answers
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Why is it that the least reactive metals are the best electrical conductors?

Silver, Gold and Platinum are amongst the best conductors of electricity, but also the amongst the most unreactive. Since electrical conductivity depends on the number of delocalized electrons (along ...
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1answer
262 views

Why are aqua ion complexes of transition elements not solid but a solution? [closed]

Water ligands form dative covalent bonds with the central transition metal ion. That would mean a molecule is formed, just like sulfur dioxide or any other. The transition metal ion does not form ...
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2answers
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Why are there peaks in electronegativities in d-block elements?

Looking at the Pauling electronegativities in the Periodic Table (below, from ChemWiki): Asides from the overall trend of increasing electronegativity across and up the Periodic Table (towards ...
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4answers
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Why is zinc deposited on copper when boiling an aqueous zinc sulfate solution?

I did an experiment where I dissolved 30 grams of zinc sulfate in water and boiled it with strips of solid zinc metal and strips of copper metal and a layer of zinc was deposited on the copper. I ...
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1answer
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Why do transition metals form particularly stable complexes?

The pre-transition metal ions can form complexes but the ligands are weakly bound unless they are multidentate and thus benefit from the chelate effect. For example, crown ethers and cryptands. ...
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1answer
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Manganese(VII) oxidation state

A transition element is one which forms one or more stable ions which have partially filled d-orbitals. Manganese (Mn) could have an oxidation state of 7+, which means that it will lose all of the $\...
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Stability of transition metals in aqueous solution

Which is more stable in aqueous solution: $\ce{Cr^3+}$ or $\ce{Mn^3+}$? Why? My approach: $\ce{Cr^{3+}}$ should be more stable as the $\ce{3d}$ electrons will enter the $\mathrm{t_{2g}}$ orbitals. ...
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1answer
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Why don't ligands affect the oxidation state of the central metal ion?

If $\ce{Fe^3+}$ were complexed with 6 $\ce{H2O}$ ligands, the resulting complex ion would be $\ce{[Fe(H2O)6]^3+}$, and the central metal ion would still have the same oxidation state of +3 as it did ...
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1answer
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Crystal Field Splitting of d-Orbitals in Octahedral and Tetrahedral Ligand Fields

We're learning about the Crystal Field Theory (CFT, under coordination chemistry) at school now, and my teacher mentioned that the 5 d-orbitals split into orbital sets, namely the $\mathrm{t_{2g}}$ (...
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1answer
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Molecular orbital diagram of a complex including an oxido ligand

With highly oxidized metal centers, we expect that the hydroxido ligand's proton becomes acidic and will be lost to the surrounding media, creating an oxido ligand. The oxo ligand is a $\pi$ basic ...
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1answer
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Why is hexafluoridocobaltate(III) the only common high-spin cobalt(III) complex?

Almost all $\ce{Co^3+} (\mathrm{d^6})$ complexes are low spin, including $\ce{[Co(H2O)6]^3+, [Co(ox)3]^3–, [Co(NH3)6]^3+}$ and $\ce{[Co(CN)6]^3–}$. The only common high-spin cobalt(III) complex is $\...
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1answer
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What is the nature of the Fe–O2 binding in oxymyoglobin and oxyhemoglobin?

Deoxymyoglobin ($\ce{Mb}$) is known to have iron in the +2 oxidation state; I believe this was deduced from its magnetic moment, which corresponds to four unpaired electrons in high-spin $\mathrm{d^6}$...
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1answer
985 views

Why is ruthenium(III) intensely colored in water

I was preparing a solution of ruthenium(III) chloride (aqueous) when I added some (nearly black) $\ce{RuCl3 . H2O}$ to the water. I was surprised that a tiny amount could dye the water so well, I'd ...
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3answers
554 views

Can one turn a nickel blue?

I've heard of artificial coin toning, but haven't been able to find a recipe for creating a blue (or blue-ish) nickel coin. While not a metallurgist, I work with one. She tried nitric acid, which ...
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1answer
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What's the configuration of chromium(III) in aqueous medium according to crystal field theory?

It has $\mathrm{3d^3}$ configuration, but how will we decide if they enter $\mathrm{t_{2g}}$ or $\mathrm{e_g}$ orbitals since we don't know which complex will form?
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1answer
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Why is the vanadium(3+) ion paramagnetic?

I know that the electron configuration of vanadium is $[\ce{Ar}]\mathrm{4s^2 3d^3}$. None of the electrons in the 3d subshell are paired. Once it loses these three electrons, shouldn't the remainder ...
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1answer
883 views

Fe with different charges

Taken these reactions: \begin{align} \ce{2\overset{0}{Fe} + 3Cl2 &-> 2\overset{+3}{Fe}Cl3} \tag{1}\\ \ce{\overset{0}{Fe} + 2HCl &-> \overset{+2}{Fe}Cl2 + H2} \tag{2} \end{align} Why ...
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Extraction of nickel from its ores [closed]

How is nickel mined and extracted from its ores? What are the appropriate word and chemical equations for this process?
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Transition Metals that react with Vanillin and their Complexes [closed]

My question is simply whether anyone knows what are the transition metals that the phenol group of the vanillin molecule could react with, and thereby produce discolorations. This question is ...
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1answer
94 views

How to reconcile conflict between assumed oxidation state and the most stable multiplicity from electronic structure calculations?

Consider either of the small, neutral molecules containing two Zn atoms below. If I were to determine the oxidation state of Zn from this molecule, I would formally assume each Zn to be Zn(I) in order ...
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384 views

What is the activation energy of iron rust?

Iron rusts to Geothite (FeO(OH)). What is the activation energy for this reaction? Where can I find this information?
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Toxicity of vanadium in pottery

I mix and develop glaze recipes for midfire stoneware (fired to 1220°C). The colorants in pottery are mostly iron, copper, cobalt, tin, titanium, chrome, and a few other transition metals. Many of ...
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1answer
145 views

Manganates (II)

I want to ask about character of manganese(II) compounds. I read that $\ce{MnO}$ is basic, just like $\ce{Mn(OH)2}$. I started doing research and I read ions like $\ce{MnO2^{2-}}$ and $\ce{HMnO2^-}$ ...
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2answers
585 views

Number of unpaired electron and total spin angular moment

IIT-JEE advanced 2013 has a question: Give the correct order of the complex ions given below according to their spin-only magnetic moment: A. $\ce{[FeF6]^{3-}}$ B. $\ce{[V(H2O)6]^{2+}}$ C. $\...
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1answer
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Why is the tetraamminecopper(II) ion square planar?

The tetraamminecopper(II) ion is square planar in shape. But why? How can I rationalise this? Can I rationalise this without the concept of hybridization? And even if I take hybridization into ...
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1answer
180 views

Symmetry and SALC: choosing coordinate basis

When we construct symmetry adapted linear combinations of orbitals (aka SOs) to build an MO diagram, we choose the z axis as the axis of highest symmetry and all other axis to make symmetry operations ...
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Relative orbital energies of Mn and Ni

In this MO diagram, why are the atomic Mn $3d$ orbitals higher in energy than the Ni $3d$ orbitals?
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1answer
108 views

Metals Vapor Pressure [duplicate]

I know metals like copper, silver and gold for example have vapor pressures at high temperature but do their vapor pressures still exist at standard temperatures (290 kelvin) and pressures (100 ...
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0answers
317 views

Calculation of Bond/Angle/Dihedral force constant

I am a big fan of Mopac (Though I have a very little knowledge about the tool). I have some queries regarding some calculations in Mopac2016: Problem: How to calculate Bond or Angle or Dihedral ...
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1answer
186 views

Different chemoselectivity of transition metals in catalytic hydrogenation

I am quoting my Clayden et al 2nd edition: Some catalysts are particularly selective towards certain classes of compound – for example, Pt, Rh and Ru will selectively hydrogenate aromatic ...