We’re rewarding the question askers & reputations are being recalculated! Read more.

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].

Filter by
Sorted by
Tagged with
5
votes
1answer
2k views

Yellowish tinge during titration of oxalic acid with potassium permanganate

One of the our chemistry practicals involve finding the molarity of an oxalic acid solution by titrating it with standard $\ce{KMnO4}$ solution. The oxalic acid solution is heated and little sulfuric ...
-2
votes
1answer
81 views

If a transition metal loses electrons so easily, how does it maintain its integrity?

If a transition metal can lose electrons so easily, then after it has been used for a conductor for x amount of time, why doesn't it fall apart? If electricity can flow through it because of loose ...
11
votes
4answers
4k views

Are complex ions thermochromic?

Does raising the temperature of a complex ion (formed from a transition metal ion and ligand(s)) affect its color? For example, if the temperature of $\ce{[Cr(H2O)6]^3+}$ is raised, will its color ...
0
votes
1answer
1k views

Oxidation number in Coordination Compounds

How to determine the oxidation number of the central metal atom in case both cation and anion is a complex? For example: [$\ce{Pt(NH3)4}$][$\ce{PtCl6}$]
1
vote
1answer
6k views

How to find out the charge of a complex?

Technetium forms a complex with merceptoacetyltriglycine ($\ce{MAG3}$), but I don't know where the negative charge of the technetium complex comes from. The oxidation state of technetium is $\mathrm{+...
8
votes
0answers
16k views

Mechanism for an Étard reaction (chromium complex)

In the following reaction, a chromium complex is formed during the Étard reaction: I have the following questions: How is this complex formed? How does its hydrolysis take place? (What's the ...
1
vote
1answer
3k views

Total valence electrons in a rhodium complex

How many valence electrons does the following metal complex have? I have read that benzene donates 6 electrons to a transition metals valence electrons. Rh has 9 from itself, and H and Cl add 1 ...
0
votes
2answers
3k views

Why is CrCl3 acidic?

Why is $\ce{CrCl3}$ acidic? I know that it has a high charge density given that it is a transition metal ion, and can hence polarize neighbouring water molecules, resulting in hydrolysis and formation ...
3
votes
0answers
398 views

Why doesn't beta hydride elimination happen in alkenyl/aryl halides?

Beta hydride elimination is an important reaction in organometallic chemistry: This reaction prohibits the use of saturated alkyl halides in coupling reactions, because it can take place after ...
7
votes
1answer
94 views

Does a certain “Badecker reaction” actually exist?

A book I read, mentions a certain Badecker reaction under coordination chemistry. It goes like this: $$\ce{Na2[Fe (CN)5 NO] + Na2SO3 -> Na4[Fe (CN)5 (NOSO3)]}$$ I googled up the name, but I didn'...
6
votes
0answers
564 views

Why are the electronegativities of transition metals so similar to each other?

I was wondering why the electronegativity among transition metals are so similar. I can't find anything on the internet, just vague answers about the d orbitals that don't seem to provide a sufficient ...
6
votes
1answer
15k views

Dehalogenation of vicinal dihalides

Why, among different metals, only zinc is favourable for the dehalogenation of vicinal dihalides?
4
votes
0answers
123 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-...
5
votes
1answer
2k views

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 $\mathrm{t_{2g}}$ (...
2
votes
2answers
3k views

Why are transition metals said to have different valencies?

I understand that the term valency refers to the number of bonds an element would be able to form with either chlorine or hydrogen. If this is directly related to the number of valence electrons an ...
2
votes
0answers
100 views

Selectivity of catalysts

What is the reason behind the fact that methane on controlled oxidation gives methanol in presence of Cu catalysts whereas formaldehyde is obtained if we use molybdenum oxide ($\ce{Mo2O3}$)? IUPAC ...
1
vote
0answers
37 views

Why are the electronegativities of elements in the middle of the transition groups quite high compared to surrounding elements? [duplicate]

Is it something to do with the d orbital being used, and if so, what effect does this have and why does it make the electronegativity higher?
4
votes
1answer
2k views

Why are fluorides of transition metals unstable in low oxidation states? [duplicate]

Why are fluorides of transition metals unstable in low oxidation states? I would think that since fluorine and oxygen are highly electronegative, it's obvious that they be stable at high oxidation ...
5
votes
1answer
3k views

What type of bonding is there among d-block metals?

Metallic bond strength in $\mathrm{d}$-block elements increases up to the middle and then decreases. Why does pairing decrease the strength of metallic bond? What does pairing have to do with metallic ...
1
vote
2answers
1k views

Copper metal with silver ion

My book states that $\ce{2AgNO3(aq) +Cu ->Cu(NO3^-)2(aq) +2Ag(s)}$. In addition to the formula, it also shows the following image: As in the image it shows the salmon colored copper atoms are ...
4
votes
1answer
549 views

Why do better π-acceptor ligands cause smaller Δ(T) d-orbital splitting?

Consider a formazanate ligand. Then imagine an electron-withdrawing group added to it. I expect a small σ-donating effect, and good π-accepting properties. My supervisor tells me that an ...
5
votes
4answers
6k views

Why is MnO2 not a peroxide?

As I know, $\ce{MnO2}$ is called manganese(IV) oxide. Why can't we name it manganese peroxide since manganese(II) exists too? In other words, how do we know that the oxidation number of manganese in ...
0
votes
1answer
359 views

How to make γ-MnO2 in a lab?

I am working on Li-ion batteries, and I need to use γ-$\ce{MnO2}$ (electrolytic manganese dioxide). I have googled and read quite a few papers, but I am not very sure of those methods. I'd love ...
8
votes
1answer
946 views

Sodium permanganate from manganese dioxide and sodium hypochlorite

This page states that sodium permanganate can be formed by the reaction of manganese dioxide with sodium hypochlorite and sodium hydroxide: $$\ce{2 MnO2 + 3 NaClO + 2 NaOH -> 2 NaMnO4 + 3 NaCl + ...
28
votes
1answer
515 views

d-orbital splittings in WS2 monolayer

The formerly degenerate $d$ orbitals of the tungsten atoms in the $\ce{WS2}$ monolayer are split into three groups: (1) $\mathrm{d}_{z^2}$, (2) $\mathrm{d}_{x^2-y^2}, \mathrm{d}_{xy}$ and (3) $\mathrm{...
0
votes
1answer
72 views

The most variant groups of periodic table

Is it okay to call group 11 (formerly 1B) a "group"? I meant that according to my knowledge "A group is a horizontal column consisting of elements with similar valencies and a continuous gradation in ...
0
votes
1answer
1k views

How to determine the percentage of iron(II) and iron(III) in a solution?

Outline a plan of an experiment to determine the percentage of iron present as iron(III) in a solution containing $\ce{Fe^3+(aq)}$ and $\ce{Fe^2+(aq)}$ ions. You are provided with zinc, a standard ...
1
vote
1answer
5k views

How does chromium(III) react to form chromium(VI) with hydrogen peroxide?

$$\ce{2Cr(OH)3 + 4NaOH + 3H2O2 -> 2Na2CrO4 + 8H2O}$$ How does this reaction occur? We suddenly get sodium chromate in the place of chromium hydroxide. I can't understand it. We mix two hydroxides ...
7
votes
1answer
209 views

Why doesn't the bidentate ligand form dative bonding three times?

I was looking at this question where it asked you to work out the final complex formed when an excess of 1,2-diaminoethane is added to and aqueous solution of copper (II) sulphate. So the equation I ...
1
vote
1answer
170 views

Transition Metals colours and electron absorbtion

I understand that when d-orbitals split some electrons can occupy the higher orbitals by absorbing frequencies of light, but do these electrons then fall back to their original ground states? If so, ...
1
vote
0answers
47 views

Why would a reaction take place in this instance?

This makes little sense to me, both of the electron configurations are d6, and would presumably be low spin - therefore both reactants should be inert, and yet my notes suggest that an electron ...
3
votes
1answer
561 views

How to determine the magnetic character of heteroleptic complexes?

I was asked to find out the magnetic behavior (and essentially electronic configuration) of heteroleptic complexes using Valence Bond Theory and Crystal Field Theory. But I am confused about how to ...
2
votes
2answers
5k views

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 $\...
4
votes
0answers
548 views

Can oxidation of ethanol by copper(II) oxide yield copper(I) oxide as one of the products?

We know that ethanol is oxidised by copper(II) oxide to an aldehyde. Copper is reduced from $\ce{Cu^2+}$ to $\ce{Cu}$. Can this reaction, with some specific condition, yield $\ce{Cu2O}$ instead? That ...
20
votes
3answers
6k views

Why is manganese(II) coloured although the transition should be spin-forbidden?

In every basic coordination chemistry class, at some early point the crystal field theory and LFSE will be taught, explaining that there will be an energy difference between d-orbitals (typically ...
-1
votes
1answer
466 views

Why Does Coordination of Metal Ions Happen Anyways?

I've been studying coordination chemistry, but I still have a fundamental question about the area: why do transition metals even form coordination compounds, while main group metals do not? Why can't ...
2
votes
2answers
3k views

Metallic and magnetic nature of transition metal oxides

Which of the following oxides is both metallic and ferromagnetic: $\ce{VO2}$, $\ce{CrO2}$, $\ce{MnO2}$, $\ce{TiO2}$? This is how I went about solving it: Since ferromagnetic materials also show ...
4
votes
0answers
145 views

Why is platinum an excellent catalyst in comparison with similar metals? [duplicate]

What is special about platinum structure which actively participate in catalytic reactions while similar metals with similar atomic structures cannot.
1
vote
0answers
126 views

Nickel(II) + borohydride debenzylation reaction mechanism

I've been looking at this reaction for cleavage of benzyl esters. I've also looked at the original paper and some others, but haven't been able to find any mechanism on how this reagent does ...
16
votes
2answers
833 views

Why is WF6 stable whereas CrF6 is unknown?

$\ce{F-}$ is a hard base since it is small and relatively polarizable. Both $\ce{Cr^6+}$ and $\ce{W^6+}$ are hard acids, but shouldn't $\ce{CrF6}$ be favored since it would be a smaller hard acid?
2
votes
1answer
6k views

Does crystal field splitting energy Δ increase going down a group of transition metals if the ligands are weak field?

Going down a group, the metal orbitals are more diffuse so there is greter overlap between the metal and the ligand orbitals. If there are no π-interactions, i.e. with σ-donor ligands like $\ce{NH3}$, ...
1
vote
1answer
267 views

How to decide from the solubility product constants which hydroxide precipitates first?

Salts of $\ce{Fe^3+}$ and $\ce{Al^3+}$ are in a beaker of water. If NaOH is added slowly, what compound would precipitate first? For me, I think it's $\ce{Fe^3+}$ because of its lower $K_\mathrm{sp}$...
0
votes
1answer
2k views

How many d-electrons are in the outer shell of the metals in following compounds: [duplicate]

How many d-electrons are in the outer shell of the metals in following compounds: ZnS Do I just use Zn^2+ and as I know that in Ions the s orbitals are removed first I count 10 d electrons? However ...
0
votes
1answer
206 views

How many d-eletrons are in the outer shell of following compounds:

How many d-electrons are in the outer shell of the metals in following compounds: $\ce{ZnS}$ and $\ce{NiS}$ So sulphur does not has any $\ce{d}$ electrons and $\ce{Zn}$ has $10\ce{d}$ electrons. ...
1
vote
0answers
27 views

Melting temperature and electronegativity trends in transition metals [duplicate]

So I know that generally the melting temperature increases across the row (let's look at just the first row for now) but what are the deviations? And why do they occur? I've looked everywhere online ...
6
votes
1answer
174 views

What wavelength of light is released when an electron drops an energy level in complexes?

I know that the color of transition metals is related to the splitting of the d-orbitals. Only a certain wavelength is absorbed in the promotion of electron to a higher d-orbital and therefore the ...
1
vote
1answer
418 views

Rate of Fenton Reaction

I want to determine rate of Fenton reaction with different concentration of $\ce{Fe^2+}$. These are some questions that I have encountered: How long does it usually take for the reaction to complete? ...
2
votes
0answers
494 views

Trends in the covalency of bonding across the transition metals

I am under the impression that the covalent character in the bonding of transition metal compounds increases across a group; in fact I think this is why they're called transition metals (a transition ...
3
votes
1answer
1k views

Why can mercury(I) exist, but not zinc(I)?

Mercury shows variable valency while zinc does not. Its electronic configuration is $\ce{[Xe]\:4f^14 5d^10 6s^2}$. So it can donate the $\ce{6s^2}$ electrons and should only be able to form $\ce{Hg^2+}...
1
vote
0answers
49 views

Hydrodehalogenation of aryl chlorides

Palladium is the "go to" heterogeneous catalyst for dehalogenating aryl chlorides using hydrogen. What are the chemical (not economic) reasons for other precious metal catalysts not being as common or ...