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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6
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0answers
3k views

Is iron(III) carbonate stable in water?

I searched for this onsite already, and also found the following answer on Quora: In aqueous environment, iron(III) is bound by water molecules and exists as $\ce{[Fe(H2O)6]^3+}$. Due to strong ...
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1answer
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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 ...
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379 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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Hybridisation of Mn in potassium permanganate

I'm clear with the concepts of crystal field theory. But I can't figure out the exact reason why the hybridisation of manganese in potassium permanganate ($\ce{KMnO4}$) is $\mathrm{d^3s}$. Can anyone ...
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1answer
38 views

How is traditional thermite powder stored such that it doesn’t corrode?

I watched some guy talk about redox reactions. Then he was going to do the good old thermite demonstration. He just had a bottle of thermite mixture. I’m wondering, why didn’t it have a chance to ...
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4answers
64k views

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 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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1answer
6k views

Does iron(III) sulfate react with copper?

As my understanding, there should be an oxidation-reduction reaction: $$ \ce{2 Fe^3+ + Cu → 2Fe^2+ + Cu^2+} $$ However, I always see the process using $\ce{FeCl3}$ to etch copper, but I never ...
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145 views

Copper Mirror Reaction

I would like to create a copper mirror on a plate of sandblasted glass. I know that a reaction exists: $$\ce{CuSO4 + N2H2 -> Cu + N2 + H2SO4}$$ I know that such a plate of copper is very weak. ...
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27 views

What are Technetium's physical stress characteristics?

I've looked at periodic and data tables from several sources, but none give mechanical / engineering property data on Technetium. Why is this?
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Why is ligand substitution only partial with copper(II) ions and ammonia?

When studying ligand substitution (at UK year 13 level), the following example has been given: \begin{align} \ce{[Cu(H2O)_6]^2+ + 2NH3 &<=> [Cu(OH)_2(H2O)_6] + 2NH4^+}\\ \ce{[Cu(OH)_2(H2O)...
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Why do 3d orbitals have lesser energy than 4s orbitals in transition metals? [duplicate]

This is quoted from Jim Clark's Chemguide For reasons which are too complicated to go into at this level, once you get to scandium, the energy of the 3d orbitals becomes slightly less than that of ...
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Can hexavalent chromium be created by exposure of chromium alloys to air at room temperature?

I believe that Cr on its own (as in chrome coating) oxidizes as Cr(III) when exposed to air, and similarly I think that it is the same for Cr as a component of stainless steel. Is it always the case ...
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1answer
115 views

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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2answers
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Why is anhydrous CuSO4 White while hydrated CuSO4 is Blue? (even though both have one unpaired electron)

We all know that $\ce{CuSO4.5H2O}$ is blue and it turns to $\ce{CuSO4}$ on heating which is white. I also learnt about coordination complexes and d-d transitions and how transition metal compounds are ...
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2answers
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Why are noble metals more electronegative then most metals?

I was researching about electronegativity when I looked up what a graph of electronegativity within the periodic table is. And, this appeared. I scanned it, matching up everything I knew about the ...
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1answer
274 views

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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1answer
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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 ...
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Why is it wrong to use the concept of hybridization for transition metal complexes?

I have asked a lot of questions on coordination chemistry here before and I have gone through a lot others here as well. Students, including me, attempt to answer those questions using the concept of ...
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2answers
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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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Why does silver oxide form a coordination complex when treated with ammonia?

Part of the preparation of Tollens' reagent occurs according to the formula: $$\ce{Ag2O (s) + 4 NH3 + 2 NaNO3 + H2O → 2 [Ag(NH3)2]NO3 + 2 NaOH}$$ I wonder how exactly the oxygen gets "unstuck" from ...
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343 views

Ionization enthalpies of Transition elements

“There is generally expected increasing trend in the values as the effective nuclear charge increases. However the value[First ionisation enthalpy] of Cr is lower because of the absence of regarding ...
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4answers
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Why is Cr(2+) a stronger reducing agent than Fe(2+) in water?

According to me, $\ce{Fe^{2+}}$ should be a better reducing agent because $\ce{Fe^2+}$ - after being oxidized - will attain a stable $\ce{d^5}$ configuration, whereas $\ce{Cr^2+}$ will attain a $\ce{d^...
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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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2answers
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How can titanium burn in nitrogen?

I was going through the properties of titanium when a certain thing caught my eye: It was the reaction of burning of titanium in nitrogen. I was astonished to read it as I knew that neither is ...
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4answers
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Colour of Nickel thiocyanate

What is the colour of $\ce{C2N2NiS2}$ (Nickel thiocyanate)? In most of the web sites it only molecular weight,formula and other specifications but its colour is missing every where.
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1answer
492 views

Why does chlorine oxidise iron to iron(III), not iron(II)?

I was asked to predict the product of the reaction between iron metal and chlorine gas: $$\ce{Fe +Cl2->} ?$$ The product here is supposed to be $\ce{FeCl3}$. But how would we know if the product ...
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1answer
700 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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Rhombohedral second-order Jahn–Teller effect in Au(II) complex?

I was recently listening to a talk about the following work[1] when the author mentioned that they explained the following. In this $\ce{Au(II)}$-porphyrin complex you observe two sets of $\ce{Au-N}$ ...
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1answer
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How does aqua regia dissolve gold?

I recently learned that aqua regia can dissolve less reactive or noble metals like gold. Aqua regia is a mixture of $\ce{HCl}$ and $\ce{HNO3}$, but separately, neither of these acids dissolve gold. ...
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1answer
111 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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2answers
50k views

Why does Co2+ have 7 electrons in the 3d orbital, and not 5 like Mn?

I'm taking general chemistry 2 this half of the summer. We are currently going over coordination complexes, ligands and transition metal ions. In particular, this question is in regards to the ligand ...
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0answers
263 views

Molecular orbital diagram for terminal metal-oxo complex with dative bonds

I am interested in terminal metal-oxo complexes and their electronic structure, specifically those with coordination numbers of 6, including the oxo ligand. I know that Fe(IV)-oxo complexes tend to ...
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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 ...
38
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1answer
959 views

Relativistic effect: d-electrons in metallorganic complexes

With higher period the d-electrons of the metal are less strong bonded and therefore oxidative addition is easier for $\ce{Ir(I)}$ than for $\ce{Rh(I)}$ and much easier than for $\ce{Co(I)}$. For ...
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1answer
276 views

Which karat gold is harder, 24 kt or 18 kt?

$\pu{24 kt}$ gold indicates that $24/24$ part of it, i.e. $100\%$ of it is gold. $\pu{18 kt}$ indicates that $18/24$ part of it is gold. As gold is a soft element, I reckoned that $\pu{18 kt}$ gold ...
28
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1answer
529 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{...
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3answers
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Is iron the most stable element in the periodic table?

According to the binding energy per nucleon vs mass number graph, it is observed that iron-56 has the maximum value of binding energy per nucleon ($\pu{8.75 MeV}$). It means that iron-56 is the most ...
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1answer
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Dissociation rates: trans-effect rule in square planar complexes

In lecture, the trans-effect was described. A ligand $L^t$ with a higher trans-effect as $L$ (cis to $L^t$) leads to a faster dissociation of ligand $L^d$ (trans to $L^t$). I would expect that the ...
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1answer
16k views

Can metals have a net negative charge

Normal metals like sodium or Calcium have a positive charge as $\ce{Na}^+$ or $\ce{Ca}^{2+}$. Transition metals have a loot of variable oxidation states. Yesterday I read about Iridium in Wikipedia ...
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2answers
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What is the electronic configuration of Fe(II) ion?

The electronic configuration of Fe is $\ce{[Ar] 3d^6 4s^2}$. So after removing two electrons the configuration becomes: $\ce{[Ar] 3d^6}$ But why can't the electrons rearrange themselves to give a ...
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2answers
107 views

Transition metal or transition element?

With reference to the periodic table’s d-block, are the terms “transition metals” and “transition elements” interchangeable when describing these elements? Are there any situations where it would be ...
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1answer
1k views

What is the number of unpaired electrons in cobalt(II) tetrathiocyanate?

Find the number of unpaired electrons present in the d orbital (whose lobes are present along the axis) for the complex $\ce{[Co(SCN)4]^{2-}}$. Since $\ce{{SCN}^{-}}$ is a weak ligand I did not pair ...
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1answer
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While filling electrons, we follow Aufbau principle, but not while removing them. Why is this so?

I recently came across a question Why is the vanadium(3+) ion paramagnetic?, where the asker is wondering how $\ce{V^{3+}}$ is paramagnetic (he used Aufbau in reverse to remove the electrons), while ...
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1answer
912 views

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 ...
3
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2answers
4k views

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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3answers
5k views

Why do iron(II) ions and chromium have different electronic configurations?

What I know: Empty 3d orbitals are higher in energy than empty 4s orbitals Aufbau Principle (electrons always go into an empty orbital with the lowest energy) Partially/half/fully filled 3d ...
5
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1answer
55k views

Why does copper react only with nitric acid? [duplicate]

When we are entering the chapter for acid and base, one of the reactions is about reacting metal with acid to form a salt and hydrogen gas. My teacher also informed us that a metal which is at a lower ...
3
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2answers
17k views

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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1answer
40k views

Why can we smell copper?

If I can smell an object, it means that molecules of it are getting separated from it, so they can reach my nose. As far as I know, metals don't sublimate, especially not in room temperature. However, ...