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].
8
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2answers
574 views
Why is Ni[(PPh₃)₂Cl₂] tetrahedral?
Since PPh₃ is strong field ligand and, the famous Wilkinson's catalyst, which also possess this ligand is square planar, then what makes the above complex tetrahedral?
6
votes
0answers
33 views
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 $\ce{Pd(CO)(PPh3)3}...
7
votes
1answer
77 views
Reference for electronegativities of different metal oxidation states
A long time ago I was researching the effect of the self regulatory response in Fe and Co. I found that my results made sense based on the idea of the electronegativity of the ions considered. I found ...
1
vote
0answers
55 views
Why do tetrahedral organic molecules show stereo-isomerism, but not tetrahedral transition metal complexes?
Both types of molecules show different arrangements of the molecule in space, so they should qualify for optical isomerism right?
1
vote
1answer
67 views
Why do some ions form tetrahedral complexes more readily than others? [closed]
Why does Co$^{2+}$ readily form tetrahedral complexes such as [CoCl$_4$]$^{2-}$, whereas Fe$^{2+}$ usually forms octahedral complexes?
7
votes
1answer
148 views
Only d orbital electrons for spin only magnetic moment
During my chemistry lessons and self studies, I have come upon many instances where I observed that during calculations of spin only magnetic moment of transition elements only the d orbital electrons ...
0
votes
1answer
50 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 ...
0
votes
0answers
48 views
Why does copper jewelry & wire smell bad - even when I'm not wearing it?
I make jewelry by weaving a frame from copper wire for a gemstone, then making copper coils or spirals, etc for further decoration. Even 'on the roll', the copper wire smells bad - and the smell ...
0
votes
0answers
24 views
Why do heavier d block elements are more stable in higher oxidation states than lighter d block elements? [duplicate]
I read that it is because it is easier to ionise the elements as the electrons involved are those of d orbitals which have same degeneracy. First of all, i found it very vague. Secondly, what about ...
2
votes
0answers
25 views
Reactivity of Ni Vs. Pd - available oxidation states
I'm hoping someone can help me tighten up my understanding of the origins of the differences between Ni and Pd catalysis.
I understand that Ni has higher charge density and this is the reason for it'...
0
votes
0answers
30 views
Metal complexes and bonding of ligands
I am currently learning about transition metal complexes, however I keep seeing complexes like $\ce{[Al(H2O)6}]^{3+}$ but aluminium isn't a transition metal. Is this a case that any metal can form a ...
2
votes
2answers
82 views
Colour change when excess ammonia added to [Cu(H2O)6]2+
Since ammonia is a stronger ligand than $\ce{H2O}$ shouldn't the colour of the new solution $\ce{[Cu(NH3)4(H2O)2]}$ be lighter as the energy gap will be higher and so light with higher frequency and ...
2
votes
1answer
264 views
How to determine the greatest d orbital splitting?
This question comes specifically from an IB Chemistry HL Paper 1 in May 2018 TZ1, namely question 8.
Which complex has the greatest d orbital splitting?
It gives 4 Complexes $\ce{[Fe(H_2O)_6]^{2+}}$,...
2
votes
0answers
16 views
Metal catalysts used in C-H bond functionalisation [closed]
Why are the late transition metals used for C-H bond activation/functionalisation? What atomic properties of the late TM make them attractive for coordinating C-H sigma bonds?
Thanks.
1
vote
1answer
48 views
How to convert soluble colorless [HgI₄]²⁻ back to insoluble red HgI₂? [closed]
When a solution contains $\ce{Hg^2+}$ and $\ce{I-}$, depend on the concentration ratio of $\ce{Hg^2+}$ and $\ce{I-}$, the following reactions can happen:
$$\ce{Hg^2+ + 2 I- ⟶ \underset{insoluble red ...
0
votes
0answers
27 views
ML6 Type Coordinate Complexes - Drawing a Molecular Energy Orbital Diagram
In class we recently discussed how to draw out molecular orbital energy diagrams for compounds such as NH3 (ammonia). Building upon this, we touched on how to construct a molecular energy diagram for ...
1
vote
0answers
47 views
Qualitative analysis of iron(III) salt
Why will $\ce{Fe^3+}$ give brown ring test?
In my textbook it was given that ferric ion gives brown ring too. I am confused, if ferric ion is already present, then what will reduce nitrate ion to ...
0
votes
1answer
188 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-...
1
vote
1answer
54 views
Aqueous copper and how it reacts with NH3
I have learnt that you can test whether an unknown metal is copper by doing a simple test tube reaction. The reaction involves adding aqueous $\ce{NH3}$ to the test tube which contains the copper.
...
3
votes
2answers
165 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+}$ ...
1
vote
1answer
30 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 ...
3
votes
0answers
48 views
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 ...
1
vote
0answers
62 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}$$
I know that such a plate of copper is very weak. ...
0
votes
0answers
23 views
What are Technetium's physical stress characteristics?
I've looked at periodic and data tables from several sources, but none give mechanical / engineering property data on Technetium. Why is this?
2
votes
0answers
39 views
Can hexavalent chromium be created by exposure of chromium alloys to air at room temperature?
I believe that Cr on its own (as in chrome coating) oxidizes as Cr(III) when exposed to air, and similarly I think that it is the same for Cr as a component of stainless steel.
Is it always the case ...
1
vote
1answer
80 views
Why does ligand substitution occur when OH- is a better ligand than NH3?
$$\ce{[Cr(H2O)3(OH)3](s) + 6NH3 -> [Cr(NH3)6]^3+ + 3H2O + 3OH-}$$
When excess $\ce{NH3}$ is added to triaquatrihydroxychromium(III), why does ligand substitution occur when $\ce{OH-}$ is a better ...
0
votes
2answers
69 views
How to balance this redox reaction taking place in a basic medium?
How to balance this reaction which is taking place in a basic medium?
$$\ce{Al + MnO4- -> MnO2 + Al(OH)4-}$$
My Attempt
Reduction half reaction:
$$
\begin{align}
\ce{4 H+ + MnO4- + 3 e- &-&...
2
votes
2answers
223 views
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, ...
1
vote
0answers
101 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 ...
3
votes
0answers
44 views
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 $\pu{5E-3 M}$.
...
0
votes
1answer
322 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 ...
3
votes
1answer
155 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 + ...
4
votes
0answers
37 views
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 $\ce{Au-N}$ ...
2
votes
0answers
188 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 ...
0
votes
1answer
63 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 ...
4
votes
1answer
144 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 ...
4
votes
2answers
433 views
Considering the d-d transition how, does tetracyanidonickelate(II) ion exist as a colored complex?
As I refer on google, the resources indicated that,
the d block elements which have unpaired electrons as in their ions, when they are making complexes with ligands, they can absorb different ...
4
votes
2answers
73 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 ...
-2
votes
1answer
371 views
Why do NON -Transition elements exhibit variable oxidation state?
I know transition elements exhibit variable oxidation states because valence electrons are in d block and s which are very close so they have similar energies ,thus with slightly different energies ...
0
votes
0answers
498 views
Compare stability of transition metal cations in aqueous solution
I have to compare the stability of the following transition metal cations: $\ce{Co^3+, Fe^3+, Cr^3+, Sc^3+}$ in aqueous solution. (Source: Joint Entrance Exam (JEE) 2013 Mains India)
The first thing ...
0
votes
1answer
537 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 ...
0
votes
1answer
724 views
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 ...
2
votes
1answer
229 views
ligand pi system irreducible representation for trigonal bipyramidal transition metal complex
I am considering a D$_{3h}$ trigonal bipyramidal transition metal complex MX$_5$. I have found that the irreducible representation for the ligand s and $\sigma$ systems is 2A$_1'$+A$_2''$+E$'$. I ...
1
vote
1answer
97 views
What are the magnetic properties of [Ni(S2C2Ph2)2]^z's 3 oxidation states?
I was doing some research on Wikipedia and I came across the article on non-innocent ligands. It talked about the chemical $$[\ce{Ni(S_2C_2Ph_2)_2}]^z$$ as an example. It mentioned that the transition ...
1
vote
0answers
137 views
Color of potassium permanganate and potassium dichromate [duplicate]
In $\ce{KMnO4}$, the Oxidation state of $\ce{Mn}$ is +7, which results in an electronic configuration as $\ce{[Ar] 4s^0 3d^0}$
In $\ce{K2Cr2O7}$,the Oxidation state of $\ce{Cr}$ is +6, which results ...
1
vote
0answers
870 views
The irregular trend in ionization enthalpy of 3d elements
The d block elements display several exceptional behaviours, and one of them is the irregular trend in ionization enthalpy of 3d elements.
The reason given by my textbook is very confusing, which I'...
3
votes
1answer
314 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 ...
0
votes
1answer
88 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 ...
0
votes
1answer
52 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 ...
1
vote
0answers
330 views
Why do transition metals make colored compounds despite the remaining d orbitals being hybridized? [closed]
I know that transition metals make colored compounds when they forms a bond with a ligand, as the ligand increases the energy level of $\ce{d_{x^2-y^2}}$ and $\ce{d_{z^2}}$ orbital by repelling these ...
