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 transition metal ions in-taken? [closed]

I have a question from my lecturer, the topic was "Toxic transition metal ions and their harms to human health". He asked me "How are these metal ions in-taken?. I'm not sure how to ...
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Why does the basic properties of oxides of transition metal increase downwards?

I was solving questions on d-block elements and I got a question that asked for the order of basic properties of $\ce{ZrO2}$ & $\ce{HfO2}$. Based on what I have learnt, the size of zirconium and ...
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Why cannot HF form dative bonds with transition metallic ions?

Since fluorine in HF has three lone pairs of electrons, but why does it still cannot form dative bonds?
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NO coordination linear vs bent - valence electron

I'd like to count the total valence electron of following neutral complex in the ionic counting (=donor-pair): Electron count: $$\begin{align} \ce{Cl-} : \ce{6e-} \\ \ce{CH3-}: \ce{2e-} \\ \ce{PPh3} :...
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Why does titanium have lower affinity than scandium?

Electron affinity of atoms in the same row usually increases with the atomic number until the shell or half-shell gets full, and then it drops down. Some transition metals are exceptions from the rule,...
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Exchange energy of d6 configuration

In NCERT Chemistry book, it is given as: Exchange energy is responsible for the stabilization of energy state. Exchange energy is approximately proportional to the total number of possible pairs of ...
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2answers
14k views

Regular decrease in the atomic radius of 3d series

While comparing atomic radius, two factors are important: A. Decrease in size due to increase in effective nuclear charge B. Increase in size due to increase in shielding effect I was surprised to ...
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2answers
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Does pure iron not rust?

In my school science textbook, written more than twenty years ago, it said that pure iron does not rust. Accompanying was a photograph of an ancient iron statue situated outside, which had not rusted. ...
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How to compare magnetic moment of chromium(III) and cobalt(II) ions?

Is there any way of comparing the magnetic moments of $\ce{Co^2+}$ and $\ce{Cr^3+}$ gas phase ions by just going through their electronic configuration?Or is it just experimental data?
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How can we predict the formula of a coordination compound by just knowing the ligand and central metal? [closed]

Question: On complete reaction of $\ce{FeCl3}$ with oxalic acid in aqueous solution containing $\ce{KOH}$, resulted in the formation of product A. The secondary valency of $\ce{Fe}$ in the product A ...
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Does concerted oxidative addition follow first-order kinetics?

So my professor for organometallic chemistry described the different mechanisms for oxidative addition and in talking about the concerted mechanism he said that it had first order kinetics. I find ...
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Density of d-block elements

Something that confuses me slightly is the trends in density when comparing periods 4, 5, and 6 in the d-block. Looking at periods 5 and 6, the density peaks at group 8, with ruthenium and osmium, ...
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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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Hybridisation of cobalt in tris(oxalato)cobaltate(III)

Will the hybridisation of of $\ce{Co}$ in $\ce{[Co(C2O4)3]}^{3-}$ be $\mathrm{sp^3d^2}$ or $\mathrm{d^2sp^3}$? The question in which I found it has mentioned the answer to be $\mathrm{d^2sp^3}$ while ...
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Why is it advised to use neutral ferric chloride solution while performing confirmatory test for acetate ions? [duplicate]

The reaction of $\ce{FeCl3}$ with $\ce{CH3COO-}$ is $$\ce{3Fe^{+3} +6CH3COO- +H2O<=> [Fe3(OH)2(CH3COO)6]^{+} +2H^{+}}$$ Recently I read that a solution of $\ce{FeCl3}$ hydrolyses very quickly to ...
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How does copper oxidise alcohols?

Consider for example ethanol being heated in the presence of copper at 300 °C. How does it give ethanal as a product? Copper being in its elemental state (oxidation state 0). Since negative oxidation ...
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1answer
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Chemical test for ferrous ions

I have a reference sheet for inorganic analysis which says that the confirmatory test for ferrous ions is as follows: Make a solution of the given salt (whose cation is to identified) and add ...
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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?
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Is tetrachloridocuprate(II) formed when dilute hydrochloric acid is added to a solution containing tetraamminecopper(II)?

As observed in the lab, when concentrated $\ce{HCl}$ is added to a solution of deep blue $\ce{[Cu(NH3)4]^2+}$ a green color appears indicating the partial formation of the yellow colored $\ce{[CuCl4]^...
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Explanation of the trans-effect (thermodynamic and kinetic) for octahedral transition metal complexes

The thermodynamic trans effect refers to the ground state weakening of the metal-ligand bond in a complex by a ligand trans to it. The kinetic trans effect is the lablisation of a ligand in a complex ...
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Why are palladium and platinum carbonyls unstable at room temperature?

By palladium and platinum carbonyls, I mean the mononuclear, homoleptic, charge-neutral, binary carbonyl complexes of the form $\ce{M(CO)_n}$ and not any heteroleptic complexes like $\ce{Pd(CO)(PPh3)3}...
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1answer
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Can aqua regia/royal water dissolve lead? [duplicate]

As known aqua regia can't dissolve $\ce{Ag}$ because formation of $\ce{AgCl}$ precipitate. Similarly will aqua regia precipitate $\ce{Pb}$ as $\ce{PbCl2}$? OR It is not possible to observe this ...
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Can aqua regia/royal water be produced with sources of chloride and nitrate other than hydrochloric acid and nitric acid?

According to Professor Poliakov and a question on Chemistry Stackexchange here, gold dissolves in aqua regia because the nitrate ion oxidizes the gold into $\ce{Au^3+}$, and the chloride bonds to the ...
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Why isn't the American nickel magnetic?

I never thought that modern American nickels actually contained nickel anymore. However, according to this wiki article, the coins actually do contain 25% nickel, the rest being copper. And yet, no US ...
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Do all metal nitrates give nitrogen dioxide on decomposition?

Some metal nitrates decompose to give nitrites: $\ce{2MNO3 -> 2MNO2 + O2}$ whereas some metal nitrates decompose to give $\ce{NO2}$. A possible reaction is $\ce{M(NO3)2 -> MO + NO2 + O2}$ Based ...
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2answers
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Why is osmium(VIII) oxide so toxic?

Osmium(VIII) oxide or osmium tetroxide is a volatile chemical compound with the formula of $\ce{OsO4}$. It is highly toxic for supposedly irritating mucous membranes, but I'm not too sure if it is ...
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3answers
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How many transition elements are there?

I searched the internet and most of sites say there are 38 transition metals. But our textbook says that group 12 or the group of zinc can not be counted as transition metals, which already puts the ...
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Is scandium considered a transition metal?

I have seen so many conflicting answers to this question in various places so I wanted to ask it again. IUPAC defines a transition element as an element whose atom has a partially filled d sub-...
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1answer
329 views

Stability of iron(III) complexes

Amongst the following the most stable complex is: A) $\ce{[Fe(H2O)6]^3+}$ B) $\ce{[Fe(NH3)6]^3+}$ C) $\ce{[Fe(C2O4)3]^3-}$ D) $\ce{[FeCl6]^3-}$ I know that the answer should be $\ce{[Fe(C2O4)3]^3-},$ ...
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Noble gas configuration and valence shell electrons [duplicate]

I know that the maximum number of electrons within a shell is equal to 2n^2. I would think that the noble gases would reflect this but that isn’t always the case n = 1 2(1^2) = 2, this is the atomic ...
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1answer
380 views

f-electrons in chemistry of heavy transition metals

In one lecture at a recent MCR-X conference I was puzzled by a side-note "f-hole is critical to describe DoS of $\ce{IrO2}$ correctly." The context was DFT periodic plane-wave calculations ...
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1answer
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Variable oxidation state of transition metal ions

Transition metals can form stable ions with different oxidation states. But I am confused why doesn't only the most stable state exist. Let me clarify my question more: $$\ce{Ti^{2+} -> Ti^{3+} + ...
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1answer
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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 $\ce{NH_3}$ ligands, and neither coordination number or ...
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Why is lead sulfide found in nature, whereas lead oxide is less common?

This question probably applies to other heavier metals as well. The only rationalization I can figure out is that lead in the +2 oxidation state (which is most common) is a borderline soft acid and ...
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4answers
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How many valence electrons do elements in the d block have?

I just noticed that on the periodic table it doesn't say how many valence electrons there are for each column in the d block. How do I find out how many valence electrons elements in the d block have?...
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Why does Co(I) have a 3d8 configuration?

Why is the electron configuration of $\ce{Co^+}$ $[\ce{Ar}](\mathrm{3d})^8$? Since neutral $\ce{Co}$ itself has a $[\ce{Ar}](\mathrm{4s})^2(\mathrm{3d})^7$ configuration, wouldn't the ionised electron ...
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Finding the valency of transition metals in coordination complexes

I understand how to find the valency of atoms in small organic compounds. For instance, for CH4, the valency of carbon is 4, while the valency of each hydrogen is 1. But for a coordination complex, ...
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1answer
222 views

Magnetic properties of potassium manganate(VII)

According to me, $\ce{MnO4^2-}$ is paramagnetic and $\ce{MnO4^-}$ is diamagnetic. On the basis of this, the corresponding potassium salts inherit these magnetic properties, i.e. $\ce{K2MnO4}$ is ...
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Why can zinc porphyrins assume 5 coordinate geometries?

It has been reported that 5-coordinate geometries are possible and stable for Zn(II) porphyrin complexes. How do these complexes form and why are they stable when other 5-coordinate geometries of Zn(...
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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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If the ferric ion is more stable than the ferrous ion, then why is it readily reduced to the latter?

The standard reduction potential value for the ferric ion: \begin{align} \ce{Fe^3+ + e- &<=> Fe^2+} & E^\circ &= \pu{0.77 V} \end{align} The value is positive, hence it means that ...
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1answer
188 views

precipitation reaction - cellulose in schweizer reagent reacts with acid

In the regeneration of dissolved cellulose (in a cuprammonium solution) in an acid bath, say sulphuric acid, what is the chemical reaction? There is a lot about the chemistry of the production of the ...
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114 views

Balancing redox reaction of zinc and hot diluted nitric acid

I need to balance the following reaction: $$\ce{Zn + HNO3 -> Zn(NO3)2 + NH4NO3 + H2O}$$ I assigned all oxidation numbers: $$\ce{\overset{0}{Zn} + \overset{+1}{H}\overset{+5}{N}\overset{-2}{O_3}\...
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1answer
450 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? ...
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1answer
385 views

Does iron(VI) fluoride exist?

Why does $\ce{FeF6}$ not exist? There are hexavalent iron compounds, so that is not the problem. There is the $\ce{[Fe(CN)6]^3-}$ ion, so there doesn't seem to be a steric problem.
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How to convert cell diagram to a chemical equation?

How would one convert on the right side of the cell diagram: $$\ce{Zn(s) | Zn^2+(aq) || MnO4-(aq), Mn^2+(aq), H+(aq) | Pt(s)}$$ $$ \begin{align} \ce{Zn(s) &-> Zn^2+(aq)} \tag{ox}\\ \ce{MnO4-(aq)...
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1answer
168 views

Determination of spinel structure by CFSE

$\ce{CuFe2O4}$ has inverse spinel structure, but $\ce{ZnFe2O4}$ has normal spinel structure. Explain. I know that normal spinels have a structure like $\ce{(A^{II})^{tet}(B^{III})^{oct}_2O_4}$-like ...
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Invisible spin allowed transitions in Tanabe-Sugano diagrams

In class we are looking at Tanabe-Sugano diagrams, more concretely at transitions for a d2 complex. I understand that the only spin allowed transitions are those that have a triplet state, therefore ...
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1answer
40 views

Fluorescence quenching by palladium(II) vs. platinum(II) complexes

Why do we observe much stronger (in most cases complete) fluorescence quenching by $\ce{Pd^2+}$ than $\ce{Pt^2+}?$ I work with complexes of both metals and there is no real 100% explanation I can find ...
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Comparison of C=O bond strength in metal carbonyls

Find the weakest $\ce{C=O}$ bond among $\ce{[Mn(CO)6]+},$ $\ce{Fe[(CO)5]},$ $\ce{[Cr(CO)6]}$ and $\ce{[V(CO)6]-}.$ I thought the $\ce{C=O}$ bond strength would be lowest in $\ce{[V(CO)6]-}$ since the ...

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