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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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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293 views

Diastereoselective epoxidation of acyclic alkenes with VO(acac)2

I've been reading about diastereoselective epoxidation of acyclic alkenes with VO(acac)2. This is taken from Carey, Sundberg Advanced Organic Chemistry Part B: The OH and epoxide are syn. Then, while ...
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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?
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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 ...
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130 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 ...
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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 ...
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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 ...
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109 views

Why is Iron (Fe) difficult to reduce?

$\ce{Fe^3+ + e- -> Fe^2+} \quad +0.77$ $\ce{Fe^3+ + 3e- -> Fe} \quad -0.04$ $\ce{Fe^2+ + 2e- -> Fe} \quad -0.41$ $\ce{Zn^2+ + 2e- -> Zn} \quad -0.76$ $\ce{Co^2+ + 2e- -> Co} \quad -0.29$...
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How to calculate denticity of ligands?

When looking at an ligand, how do I know its denticity? For instance, I know that though there are 2 lone pairs in $\ce{H2O}$, its denticity is only 1 due to geometrical reasons as the 2 of them can't ...
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177 views

Why tungsten does not have stable configuration? [duplicate]

Whenever there are 4 unpaired electrons in d-orbital, elements try to attain stable electronic configuration. For example copper. Electronic configuration of copper should be [Ar]3d4 4s2, but it ...
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889 views

Crystal Field Theory diagram

I need to draw a simple crystal field splitting diagram and identify the lowest-energy spin-allowed ligand field band in the electronic absorption spectrum for [MnCl6]2-. I know the basics of the ...
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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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Why are chelating ligands often used to treat poisoning by heavy metals (e.g. mercury, lead)?

Why are chelating ligands such as EDTA often used to treat poisoning by heavy metals (e.g., mercury, lead)? I have a vibe that it has something to do with the lone pairs of electrons that are able to ...
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108 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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Dichromate in acidic medium

We were taught that $\ce{Cr_2O_7^{2-}}$ (dichromate) in $\ce{H_2SO_4}$ gives $\ce{CrO_3}$ $$\ce{Cr_2O_7^{2-} +H_2SO_4 -> CrO_3 + ...}$$ Link: wikipedia But we know that dichromate in acidic ...
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Is it possible to form an alloy of gold and 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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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. ...
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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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92 views

Isolating barium(II), copper(II) and zinc(II) from aqueous solution [closed]

Q15 Each metallic ion was separated from an aqueous solution containing $\ce{Ba^2+},$ $\ce{Cu^2+},$ and $\ce{Zn^2+}$ by the procedure shown in the following figure. From ①–⑥ in the table below choose ...
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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
632 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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579 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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733 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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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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182 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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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 ...
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1answer
2k views

Valence Shell for Transition Metals

In transition metals, is the shell with the highest energy considered the valence shell? For example, in copper the electronic configuration is ${[Ar]\text{ } 3d^{10}\text{ } 4s^{1}}$. However, in ...
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139 views

Transition Metals' Charges

I came across a compound $\ce{[FeO4]^{2-}}$ but $\ce{Fe}$ has +6 charge according to my calculations. How this is possible ? Or it is possible but my periodic table is kind of non-detailed one. (On ...
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59 views

Why does this ligand form 6-coordinate complexes with Transition elements and 8-coordinate complexes with Inner transition elements? [closed]

What change takes place in the denticity of this ligand if it is an inner-transition metal ion vs a common transition metal? Primarily, why does the ligand behaves differently with the two situations ...
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86 views

How to precipitate Chloroplatinic acid? [closed]

For the precipitation reaction, I have to react $\ce{H2PtCl6}$ with $\ce{(NH4)2CO3}$ while maintaining the $\ce{pH}$ in the range of 7-8 at 60 °C. But the problem is Chloroplatinic acid is not ...
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1answer
156 views

Why is chromate coloured but tungstate colourless?

I have to try and work this out using the tetrahedral molecular orbital diagram for $\ce{[WO4]^2-}$ but I am confused as both are $\mathrm d^0$ right?
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2k views

What is the hybridization of chromium in chromate and dichromate ions?

I was recently reading about the transition metals and some important compounds of them. I came across a rather interesting diagram in my book... a tetrahedral structure for the chromate ion. The only ...
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1k views

Why do the f-block elements ( inner transition metals) have an oxidation number of +3? [closed]

The f-block valence electrons understandably include the outermost two from 6s. But why do the f-block elements have an oxidation number of +3, pulling an electron from an inner shell, not even a d-...
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156 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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2k views

Anomalous oxidation states of Transition Metals

I have noted down the available positive oxidation states of the first row of transition elements (on the Periodic Table) from the respective Wikipedia articles of the elements. $\ce{Sc} - 3, ...
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1answer
1k views

How to determine the oxidation states of the metal atoms when both cation and anion are coordination complexes?

How to determine the oxidation states of the metal atoms when both cation and anion are coordination complexes? For example, how to determine the oxidation states of $\ce{Pt}$ in the following ...
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1answer
78 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 ...
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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 ...
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3k views

Transition metal order of filling electron

There is a specific order for filling electron for transition metals, but I don't know if it applies to other elements too? Some thing to take note of in this picture is the order of 3d and 4s. My ...
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1answer
36 views

Octahedral Crystal Field Splitting Orbital Energy Levels [closed]

(image source) In the above diagram, where do the 3/5 and 2/5 come from? Also, how are the $\ce{e_g}$ orbitals degenerate with each other?
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193 views

Molar conductivity of transition metal complexes solutions [closed]

Which of the following has the highest molar conductivity? (A) Diaminedichloroplatinum(I) (B) Tetraamminedichlorocobalt(III) chloride (C) Potassium hexacyanoferrate(II) (D) Hexaaquochromium(II) ...
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1answer
58 views

Why is the reason for color different in these two cases? [closed]

I have read in a book (NCERT India) about flame color for salts of alkali metal and color of transition metal complexes. In the first case, it says that during excitation of electrons to higher ...
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886 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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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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121 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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59 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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423 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 ...
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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 ...
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1answer
323 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. ...
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54k views

Differences between Fe3+ and Fe2+ [closed]

I would like to know the differences between Fe3+ and Fe2+ ions. I'm guessing they must differ in reactivity but I'm not sure how. Also, is there a way that we can observed the differences

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