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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4
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1answer
2k views

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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320 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 ...
7
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1answer
189 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 ...
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1answer
197 views

What is the systematic name of ammonium bisoxalato cuprate (II)? [closed]

What is the systematic name of ammonium bisoxalato cuprate(II)? I already tried $\ce{(NH4)2[Cu(C2O4)2]^{2+}}$ but i am uncertain if that answer is correct.
4
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1answer
7k views

Reaction of iron(III) oxide with nitric acid [closed]

I'm currently working in a project in which I have to convert the iron oxides present in iron ore slime into ferric nitrate. Iron ore slime is which has the particle size of below $\pu{0.15 mm}$ is ...
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130 views

Asymmetric Suzuki coupling - saturated alkyl chain

9-BBN is applied for Suzuki coupling of a saturated alkyl chain with some alkenyl,alkynyl or even secondary alkyl halide like the modification attached: (Saito, B.; Fu, G. C. Alkyl−Alkyl Suzuki Cross-...
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1answer
8k views

Derivation of the Orgel diagram for octahedral d2 complexes

The Orgel diagram for a typical octahedral $\mathrm{d^2}$ complex is shown below: (source: Kettle, Physical Inorganic Chemistry, p 146) I understand that the right-hand half of the graph shows how ...
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Do Ligands electrons fill the d-orbitals of the metal ion? [duplicate]

We know that ligands make coordination bonds with d-orbitals of transition metals forming complexes. My question is, if that happened, all d-orbitals will be filled and no electron transition could ...
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1answer
193 views

Is the surface of the planet Mercury made of copper minerals?

I have been looking at photographs of the planet Mercury, and I notices that in most of the pictures I have seen, the rocks on the surface seem to be covered in blue in green. From this, is it correct ...
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In an octahedral complex, what happens to the electrons donated by the ligand?

I am trying to understand how complexes are coloured. After some reading, I found out this was due to the d-d splitting induced by the coordinate bonds of ligands to the central metal ion. The ...
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Why are Group 11 elements unreactive?

Group 11 metals namely $\ce{Cu, Ag, Au}$ are known for their low reactivities. They are thus rightly called coinage metals and have been historically used to make currency owing to this very property ...
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1answer
386 views

Formation of MnO2 vs [Mn(H2O)6]4+ in aqueous solution

I am looking for reasons why $\ce{Mn(IV)}$ wouldn't be stable as a hydrate. I know that from standard reduction potentials it exists as a ppt of $\ce{MnO2}$, but what is stopping it from being a ...
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149 views

Colour in vanadyl sulfate

What is the reason that vanadyl sulfate shows blue colour, even in its anhydrous form? If it's d-d transition, can you explain how it works in this compound?
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Is there an explanation to the atomisation energy trend of transition metals?

I am familiar with the double hump trend for atomisation of transition metals, and I can explain the unusually low atomisation of $\ce{Mn}$ with the exchange principle, specifically that in the solid ...
3
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1answer
195 views

Spectrochemical series of TMs: why does the field-splitting parameter NOT steadily increase along a period?

Why doesn't the field splitting parameter increase steadily along the period for 3rd-row transition metals, as one would expect due to a better energy match between ligands and the metal as $Z_\mathrm{...
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1answer
695 views

Is palladium on carbon acting as an oxidising or reducing agent?

In the conversion of piperidine to pyridine, palladium on carbon (Pd/C) is used. But it is reducing agent. Clear the confusion, please.
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249 views

Are lustre and conductivity directly related?

In a question that I had asked before, Is chromium the shiniest metal?, I received the answer that silver was, in fact the most lustrous metal for visible wavelengths. At the same time, silver is also ...
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2answers
13k views

What reaction takes place when potassium iodide is added to a tetraammine copper(II) complex?

I am given a blue solid W and it contains a tetraamine copper(II) complex and a $\ce{SO_4^{2-}}$. I added dilute sulfuric acid until the solution is pale blue; then added potassium iodide solution. A ...
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0answers
262 views

metallic bonding in transition metal sulfides

I searched on the internet but failed to find a clear solution for this question: Regarding transition metal sulfides like NiS or FeS, is there metallic bonding within their crystal structure? If ...
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1answer
738 views

Jahn-Teller distortion of [Fe(H2O)6]2+

I am wondering whether Fe(II) hydrated to an octahedral complex would undergo a Jahn-Teller distortion. As far as I am aware, this distortion comes about because of asymmetry in filling orbitals, in ...
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616 views

Color of complexes d-d transition or electron exchange [closed]

I always have the problem of finding whether a complex has colour due d-d transition of electrons or if it is due to electron exchange. Is there a general way to tell whether a complex has d-d ...
2
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1answer
704 views

Color transition [closed]

We have to determine which method is true in order to find which color is absorbed and which one is transmitted? I have read in an example that $\ce{Cu^{2+}}$ absorbs red light but transmits blue....
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Platinum engagement ring as oxidation catalyst [closed]

I know platinum is used in the catalytic converter to oxidize pollutants. For a pollutant ($\ce{N_xO}$, $\ce{CO}$, etc., your choice), I'd like to get an order-of-magnitude rate of catalysis, ...
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1answer
2k views

Why the ionization energy of Au is more than that of Cu?

As we go down the group from 3d to 5 d, size increases. Vanderwaal radius of Cu and Au is 140pm and 166pm respectively. Since Cu is smaller in size, ionization energy of Cu must be greater. Then ...
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101 views

HCl and chrome plated plastic [closed]

I was trying to use $\ce{HCl}$ (muriatic acid) to remove chrome plating from plastic chrome plated shower parts (shower head holder) in order to make chromium chloride. I understand that in chrome ...
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71 views

Why are heavy metal ions such as those of Hg and Cd toxic to animals?

Why are heavy metal ions such as those of Hg and Cd toxic to animals? While studying green chemistry I came to know about the Minamata disease caused by Hg and other disorders due to the accumulation ...
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Are there any stable complexes where an (N-unsubstituted) imine is bound eta^2 to a (late) transition metal?

I've been looking for an example of a stable complex where a $\ce{C=N}$ is coordinated $\eta^2$ to a (late) transition metal, but could not find any. Do they exist at all? For $\ce{C=C}$ there are ...
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3answers
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Why is tantalum so unreactive?

What is the fundamental argument behind explaining why Ta metal is so inert and does not usually participate in corrosion? I know that it forms a protective oxide, but nothing explains why in an ...
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2answers
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Why does copper(II) carbonate decompose into copper(II) oxide rather than copper(I) oxide when heated?

I recently did a lab at school surrounding the decomposition of copper(II) carbonate into copper(II) oxide, and subsequently into pure copper, when sufficient heat is added. What I don't understand is ...
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1answer
470 views

What does the reaction of chromium with ozone form?

I know almost nothing beyond 10th grade chemistry. I'm trying to name a web application, and was wondering what the products are of a reaction between the element Chromium and the gas Ozone (...
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392 views

Does Ni(H2O)6 have Oh symmetry or Th?

I optimized a geometry of $\ce{Ni(H2O)6}$ using quantum chemistry and got a molecule which is symmetrical for the $\ce{Ni-O}$ distances as shown here: In the literature it says that this complex has ...
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1answer
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Why is ZnFe2O4 a normal spinel?

Considering that $\ce{Zn^2+}$ is $\mathrm{d}^{10}$, $\ce{Fe^3+}$ is $\mathrm{d^5}$, and $\ce{O^2-}$ is a weak field ligand, the CFSE values of both the normal and inverse spinel structures should be $...
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2answers
19k views

What does the crystal field splitting diagram for trigonal planar complexes look like?

For a trigonal planar complex (e.g. $\ce{[AgCl_3]^2-}$): According to this image (source): The $x^2 - y^2$ and $xy$ orbitals are on the same energy level. However, assuming that one of the $\ce{Cl}$ ...
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1answer
1k views

Why does chromium(III) have the highest tendency to form complexes, comparatively, among Mn(III), Cr(III), V(III) and Ti(III)?

I was looking at some quick revision notes for d&f block elements and it had this random fact: Out of $\ce{Mn^3+}$, $\ce{Cr^3+}$, $\ce{V^3+}$, and $\ce{Ti^3+}$, chromium readily forms complexes. ...
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4answers
219k views

Why do transition elements make colored compounds?

Why do transition metals element make colored compounds both in solid form and in solution? Is it related to their electrons?
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4k views

Why do the halides run in reverse orders in the spectrochemical series and the trans-effect series?

Spectrochemical series: $\ce{F^-}>\ce{Cl^-}>\ce{Br^-}>\ce{I^-}$ Trans-effect series: $\ce{I^-}>\ce{Br^-}>\ce{Cl^-}>\ce{F^-}$ This seems slightly odd to me because their relative ...
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1answer
2k views

Titanium in HF vs HCl

So we tried the reaction between Titanium metal with hydrochloric acid and hydrofluoric acid at a similar concentration. While boiling temperatures and constant heat over a long period of time are ...
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1answer
708 views

How can I dissolve nickel(II) oxide?

To insulate $\ce{Pt}$ wire heaters, I plated them with $\ce{Ni}$. After switching on the heater for the first time, green $\ce{NiO}$ is formed which is insulating and protects the $\ce{Pt}$ from ...
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546 views

“Alternative” derivation of the spin-only formula

The spin-only formula $$\mu_\mathrm{so} = \mu_\mathrm{B} \sqrt{n(n+2)} = \mu_\mathrm{B}\cdot 2\sqrt{S(S+1)}$$ is usually a good first approximation to calculate the magnetic moment of transition ...
3
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1answer
69 views

Chromium +1 is unknown while Mn+2 is known?

Although both $\ce{Cr+}$ and $\ce{Mn^2+}$ both ions have $d^5$ configuration, still only $\ce{Mn^2+}$ is well-known while $\ce{Cr+}$ is not common. What is so special about Cr that it does not form $\...
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1answer
3k views

Cr(II) and Mn(III) - their oxidizing and reducing properties?

My textbook states that $\ce{Cr^2+}$ is a reducing agent while $\ce{Mn^3+}$ is an oxidizing agent in spite of both having $\ce{d^4}$ configuration. The explanation states that when $\ce{Cr^2+}$ gets ...
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2answers
2k views

How can we predict the colour of transition metal complexes?

I am facing problems in indentifying colour of complex compunds just by seeing the their molecular formula. Is there any method or concept to predict the colour of complex compunds?
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1answer
158 views

Does mercury chloride (ii) evaporate at room temperature? [closed]

if you leave mercury chloride (ii) exposed to air in a room does it evaporate to any significant level which can cause toxicity?
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1answer
125 views

How is dioxygen stabilised by coordination to haemoglobin?

I wonder how the binding of $\ce{O2}$ to a molecule of hemoglobin stabilizes it to the extent that I can carried around the body with the risk of it being involved in oxidation reactions minimized. ...
6
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1answer
566 views

Why does Mn (II) behave as “hard”?

Why, within HSAB, does $\ce{Mn^{2+}}$ behave as a hard acid? If we go across the third block, then all metals to the left of manganese form soft divalent cations (e.g. $\ce{Ti^{2+}}$, $\ce{V^{2+}}$, $...
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1answer
905 views

How many d-electrons are in the outer shell of metals like Cadmium (this is counting the 4d electrons)?

First I know similar questions have been asked about counting d-electrons. However, my question is about the electrons in the 4d orbital. For example if I have CdS. The cadmium has a charge of +2. ...
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1answer
2k views

Changing iron(III) acetate to iron(II) acetate

Is there a way simple way to turn iron(III) acetate into iron(II) acetate or vice versa? Edit (as per answer below): an oxidiser like hydrogen peroxide will turn iron(II) acetate into iron(III) ...