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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What is the reason for the anomalous electronic configuration of palladium? [duplicate]

The p block elements generally have the general valence shell configuration as $$n\mathrm{p}^{1-6}\,n\mathrm{s}^{1-2}.$$ Expected electronic configuration for palladium is $$\ce{^46Pd} = \mathrm{1s^2\,...
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How can I derive the preferred oxidation states of a transition metal from its electronic configuration?

For example $\ce{Fe}\ (Z=26)$ Short formula: $\mathrm{1s^2\ 2s^2p^6\ 3s^2p^6d^6\ 4s^2}$. If we make the electronic formula we get 4 single electrons ($s=1/2$), which means that the valence in normal ...
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Does sodium form complexes like transition metal ions?

I realise that there is a similar question here Difference between sodium ion and a transition metal ion dissolving in water? and it seems to answer my question, however I was reading about how ...
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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+}...
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279 views

Can we goldify metals?

I've read in some book that one of the old chemists was able to transform cheap metals into gold. I know that gold is an element (Au) so we can't transform a metal into Au. But as I read further it ...
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346 views

Is Fe(OH)2 soluble in alkalis?

I have just started inorganic chemistry in school and I have just learnt about metal aqua ions and how they react in water. I learnt that $\ce{[Fe(H2O)6]^2+}$ reacts in water by losing a $\ce{H+}$ ...
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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 are transition metal hydroxides insoluble?

From what I understand, adding $\ce{NaOH}$ to a solution containing transition metal ions gives transition metal hydroxide precipitates. Why is $\ce{NaOH}$ soluble but transition metal hydroxides ...
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766 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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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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How do you determine the hybridisation state of a coordinate complex?

If an exercise asks for the hybridisation state of a coordinate complex (ion in solution) consisting of a central cobalt atom surrounded by $\ce{NH3}$ ligands, and neither coordination number or ...
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What is the lattice structure of manganese?

A transition element is defined as the one which has incompletely filled d orbital in its ground state or in any one of its oxidation state. Zinc , cadmium and mercury are not typical transition ...
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Why do transition metals tend to form positive ions instead of negative ions?

I have learnt that elements on the left-hand side of the periodic table such as sodium and magnesium prefer to lose electrons to form a cation because this requires less energy to obtain a stable ...
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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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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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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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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 ...
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1answer
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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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Why are there 14 electrons in the third shell of iron atom?

The third shell must contain at least 18 electrons. But in iron there are 14 electrons in third and 2 electrons in 4th. Why are there 14 electrons in the third shell of iron atom?
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How do I determine the number and order of ligand orbitals?

I am trying to create interaction diagrams for transition metal species by reducing the representations for both $\sigma$ and $\pi$ ligand orbital sets and mixing them with the metal orbitals. The ...
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2answers
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Separating nickel coin into copper and nickel components

I'm trying to create a high school level lab in which we separate the metals in an alloy. The objective is to understand and apply standard reduction potentials, and also to do some extra redox ...
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Calculating percentages of microstructures in equilibrium phase diagrams (engineering)

So I have an equilibrium phase diagram of steel and I am asked to 'Calculate the proportion of pearlite in the microstructure of 0.4 wt% C steel just below the eutectoid temperature (727 °C).' I have ...
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Transition metal and complexation

When can we say that such metal forms a complex? Are $\ce{Pd(OAc)2}$ and $\ce{Pd(PPh3)2Cl2}$ complexes?
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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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1answer
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Spectrochemical Series - Sigma Donor Capability

I fully understand and recognise the manner and which the series works. I cannot find any references for the change in sigma donor capability moving up the series. For example, comparing $\ce{Cl-}$ ...
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1answer
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Why does $\text{Cr}^{3+}$ not have the same electron configuration as $\text{Sc}$?

To be explicit, $\text{Cr}^{3+}$ and $\text{Sc}$ have the same number of electrons, the only difference is the nuclear charge. This is not an isolated anomaly, it seems: the book I'm using claim ...
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1answer
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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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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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1answer
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Why is Cr²⁺ is a good reducing agent but Mn³⁺ is a good oxidising agent?

The question is the same as the title states. In my text book,the following is written $\ce{Cr^{2+}}$ gets converted to $\ce{Cr^{3+}}$ as the +3 oxidation state hase half filled $\mathrm{t_2g}$ ...
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1answer
295 views

Metal-Ligand-Complex and bond directions: What defines coordinate system of the complex ion? [duplicate]

I have a question concerning metal ligand complexes. In every chemistry text book I have read which treats metal ligand complexes, following situation is discussed: When 6 ligands (in octahedral ...
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Why are the Covalent Radii of Ruthenium and Osmium So Similar?

Osmium and Ruthenium have covalent radii 144 and 146 respectively (according to Wikipedia). How are these values so similar when Osmium has 32 more electrons, with another filled p, s, and f orbital ...
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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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Why does some compound as given in the image below change from low spin to high spin above a particular transition temperature?

Magnetic moment sudden increase at a particular temperature is explained by CFT. But why does it happen at all?
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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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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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0answers
610 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 ...
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323 views

Why is cupric oxide more basic than cuprous oxide?

I have learnt earlier that metal oxides with higher metal oxidation states are more acidic than those with less oxidation states, but copper disobeys this rule. Why?
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Do amino groups need to be protected during a Clemmensen reduction?

In class, we learned about the Clemmensen reduction of carbonyl groups to the corresponding hydrocarbon. This is all well and good, except that it would also seem that the conditions used in the ...
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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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What is the structure of diferric hexaphenolate?

I was studying about the ferric chloride identification of phenol, where one product formed is diferric hexaphenolate. But I am having trouble drawing out the structure of it. With ferric ion having a ...
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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 ...
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1answer
567 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 ...
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56 views

How do partially protonated sulfate ligands affect a metal's charge?

I'm currently reviewing the Periana-Catalytica system and I have a question about one of the intermediates, namely $\ce{[(bpym)Pt(OSO3H)2]^+}$, which is found in the following tutorial review. How do ...
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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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What explains the very high density of osmium and iridium? [duplicate]

Iridium with a density of $22.56$ g cm-3 & osmium with $22.59$ g cm-3. Data from their respective Wikipedia pages. Only these two naturally occurring elements have such a high density. I wish to ...
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937 views

How can I dissolve copper but not zinc?

I have a zinc-body garden spray head with a brass garden hose thread stuck inside. This is actually an irritatingly common problem. Which got me wondering: What chemical means exist to dissolve ...
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Iron (II) dioxygen reaction mechanism?

Ok so I'm confused about the mechanism for this process: Now the idea here is that iron first becomes oxidised to Fe(III) by placing an electron in the antibonding orbital of dioxygen. This is ...
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Is hydrolytic polymerisation the mechanism by which the precipitate forms from the neutral complex?

From basic coordination chemistry and acid-base equilibria we understand that a metal hexa-aqua ion can be deprotonated until it's positive charge is balanced by the negative charge of the hydroxides ...
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2answers
194 views

What is the hybridisation in dimolybdenum?

Dimolybdenum's $\mathrm{4s}$ and $\mathrm{4p}$ orbitals are full. It is going to use its $\mathrm{4d}$ and $\mathrm{5s}$ orbitals to form a sextuple bond (2 $\sigma$, 2 $\pi$, 2 $\delta$). I am ...
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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 $\...