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].
378
questions
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Nature of the bonding in hexaaquaaluminium complex
$\ce {[Al(H2O)6]^3+}$ is a well-known complex ion formed by the $\ce {Al^3+}$. I have always had the understanding that only the aqua complexes of transition metal ions, such as $\ce {[Fe(H2O)6]^3+}$, ...
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0answers
30 views
Why decanted solution should be colorless when determining formula of unknown chloride?
I was following the guide “Stoichiometric Determination:
Empirical Formula of Copper Chloride”.
Under the Procedure section the following reaction is given:
Producing solid $\ce{Cu}$ from a $\ce{Cu(...
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0answers
19 views
Factors that influence the electrical conductivity of metals
The electrical conductivity of metals is a physical property of these materials. Much of the theory used to explain the electrical conductivity of metals is also based on physics understanding. ...
7
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0answers
62 views
Does tantalum and tungsten really not form amalgams?
User @Poutnik has recently answered two questions(here and here) in which he/she quoted this statement from Wikipedia:
Almost all metals can form amalgams with mercury, the notable
exceptions ...
0
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1answer
34 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(...
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0answers
24 views
Oxidation of Hexaaquachrom (II) with air
I had the reaction:
$$\ce{Cr(H2O)6^3+ -> Cr(H2O)6^2+}$$
using $\ce{Zn}$ as a reducing agent.
the colour turning from green to blue and I know that with contact with air the solution becomes ...
2
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2answers
62 views
Colour of metal complexes with the same type and number of ligands
Crystal Field Theory says that because of d-orbital splitting caused by different ligands we have 2 different energy levels for d-orbitals.
It also says that transition metals are coloured because ...
1
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1answer
39 views
Products of the reaction between chromium(III) chloride, zinc and sulfuric acid
The aim of my experiment was to make a Cr(II) aquacomplex in situ, and for that I have the reaction:
$$\ce{CrCl3·6H2O + Zn}$$
and I add concentrated sulfuric acid to it. I know that chromium(III) ...
1
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0answers
37 views
What chemical reaction could be used to make copper pennies a vibrant red?
I’m an artist working on a piece using pennies to illustrate my drawing and I need my pennies to be red in a certain portion. I’m trying not to use paint and was wondering if there was a way to make ...
-1
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1answer
52 views
Reaction of coloured metal complexes with water and sulfuric acid [closed]
Reaction of coloured metal complexes with water and sulfuric acid
I recently started researching the coloured compounds made from transition metals focusing on one with oxidation state II, so Mn,Fe,...
2
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1answer
52 views
Mixing cobalt(III) hydroxide and thallium(III) hydroxide
A simple question on solutions is driving me crazy. At this point, I think the textbook's wrong. Here's the question:
A saturated solution of cobalt(III) hydroxide $(K_\mathrm{sp} = \pu{1.6e-44})$ ...
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0answers
53 views
Definition of early vs. late transition metal
Is there an accepted definition of an early or late transition metal? I think the late transition metals start at Group 8 (including Fe), but others have said Fe is not a late transition metal. I'm ...
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2answers
743 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?
10
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0answers
76 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 $\ce{Pd(CO)(PPh3)3}...
7
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1answer
87 views
Reference for electronegativities of different metal oxidation states
A long time ago I was researching the effect of the self regulatory response in Fe and Co. I found that my results made sense based on the idea of the electronegativity of the ions considered. I found ...
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0answers
59 views
Why do tetrahedral organic molecules show stereo-isomerism, but not tetrahedral transition metal complexes?
Both types of molecules show different arrangements of the molecule in space, so they should qualify for optical isomerism right?
1
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1answer
88 views
Why do some ions form tetrahedral complexes more readily than others? [closed]
Why does Co$^{2+}$ readily form tetrahedral complexes such as [CoCl$_4$]$^{2-}$, whereas Fe$^{2+}$ usually forms octahedral complexes?
7
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1answer
171 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
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1answer
51 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
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0answers
67 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 ...
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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
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0answers
28 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'...
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0answers
34 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
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2answers
94 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
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1answer
420 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
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0answers
17 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
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1answer
53 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 ...
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0answers
33 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 ...
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0answers
57 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
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1answer
307 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
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1answer
62 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
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2answers
191 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
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1answer
34 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
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0answers
54 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 ...
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0answers
87 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}$$
I know that such a plate of copper is very weak. ...
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0answers
24 views
What are Technetium's physical stress characteristics?
I've looked at periodic and data tables from several sources, but none give mechanical / engineering property data on Technetium. Why is this?
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0answers
41 views
Can hexavalent chromium be created by exposure of chromium alloys to air at room temperature?
I believe that Cr on its own (as in chrome coating) oxidizes as Cr(III) when exposed to air, and similarly I think that it is the same for Cr as a component of stainless steel.
Is it always the case ...
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1answer
93 views
Why does ligand substitution occur when OH- is a better ligand than NH3?
$$\ce{[Cr(H2O)3(OH)3](s) + 6NH3 -> [Cr(NH3)6]^3+ + 3H2O + 3OH-}$$
When excess $\ce{NH3}$ is added to triaquatrihydroxychromium(III), why does ligand substitution occur when $\ce{OH-}$ is a better ...
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2answers
72 views
How to balance this redox reaction taking place in a basic medium?
How to balance this reaction which is taking place in a basic medium?
$$\ce{Al + MnO4- -> MnO2 + Al(OH)4-}$$
My Attempt
Reduction half reaction:
$$
\begin{align}
\ce{4 H+ + MnO4- + 3 e- &-&...
2
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2answers
319 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, ...
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0answers
136 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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0answers
48 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
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1answer
384 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
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1answer
174 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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0answers
38 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
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0answers
202 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
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1answer
67 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
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1answer
162 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
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2answers
488 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
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2answers
75 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 ...
