Questions regarding the d-block elements, group 3-12.

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Hiyama vs Sonogashira coupling

Why is Sonogashira's coupling more feasible than Hiyama's coupling when both could occur? I have seen many examples in syntheses, here is one (the penultimate reaction):
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2answers
71 views

Lewis acid and Base. Fe[H2O]6 +3

The interaction between H+ and NH3 as respectively a Lewis acid and a Lewis base is clear for me. NH3 has a lone electron pair and H+ has no electrons, or, saying politely, an incomplete duet, and can ...
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0answers
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Low melting point of Manganeese [duplicate]

Melting point of manganese is lower than that of other 3d series except copper and zinc. Melting point increases from scandium to chromium. The reason given in my book for this trend is the increase ...
3
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0answers
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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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2answers
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Method to synthesize KAu(CN)2 (or KCN)?

Every reasonably effective method of electroplating $\ce{Au}$ onto another metal's surface (e.g. $\ce{Cu}$,$\ce{Ni}$,$\ce{Ag}$, etc.) involves use of $\ce{KAu(CN)2}$ or in some cases $\ce{KAu(CN)4}$ ...
3
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1answer
54 views

Color of Anhydrous Transition Metal Salt

Why are some anhydrous transition metal salts colored? Here are some examples I found. Anhydrous cobalt(II) chloride ($\ce{CoCl2}$), with sky-blue color. Anhydrous chromium(III) chloride ...
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Titrating cobalt II sulfate in a solution with Iron II sulfate

When titrating a solution of iron II sulfate and cobalt II sulfate using EDTA can ammonium flouride be used to mask the iron II in order to quantify the cobalt II without interference?
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59 views

Inner orbital vs outer orbital complex (Tetrahedral vs Square planar)

Restricting our discussions to d block elements and their coordination compounds, Only information given to us is the formula Can you check if these are correct Octahedral (CN=6) If there is a ...
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Why do some of the transition metals go from 4s2 to 4s1 down the line [duplicate]

I was looking at the periodic table and found for instance that Cu (copper) has an equation of [Ar] 4s1 3d10. Why would this be the case? Why is the 3d orbital filling up completely before the 4s ...
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0answers
16 views

Why does stability increase down the 11th Group?

I am quite perplexed by the behaviour of transition metals. Normally I would expect that since atomic radius increases down a group, the ability of the nucleus to retain those valence electrons ...
-1
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1answer
18 views

Questions related to distinguishing dimagnetism and paramagnetism and when is there magnetic properties

If a transition metal ion has both paired and unpaired electrons, would it be considered as showcasing paramagnetism or dimagnetism? I know that Fe2+, which has an abbreviated electronic configuration ...
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47 views

How to calculate denticity of ligands?

When looking at an ligand, how do I know its denticity? For instance, I know that though there are 2 lone pairs in $\ce{H2O}$, its denticity is only 1 due to geometrical reasons as the 2 of them can't ...
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0answers
22 views

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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1answer
49 views

In crystal field theory, why do all the metal electrons enter the d orbitals and not the s orbital?

Suppose we have the complex $\ce{[Fe(H2O)6]}$. Iron has 26 electrons, and its electronic configuration is therefore $[\ce{Ar}]\,\mathrm{4s^2 3d^6}$, but in crystal-field theory, we say that the ...
0
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1answer
84 views

Differences between Fe3+ and Fe2+ [closed]

I would like to know the differences between Fe3+ and Fe2+ ions. I'm guessing they must differ in reactivity but I'm not sure how. Also, is there a way that we can observed the differences
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1answer
83 views

Why do we say metals are monoatomic in nature?

Are metals monoatomic or polyatomic in nature? For in crystalline form they also form molecular orbitals.
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1answer
90 views

Why aren't the copper(II) ions in CuSO4 precipitated by hydroxide ions from water?

From my own experience and literature, I know that $\ce{CuSO4}$ is well soluble in water and dissociates into $\ce{Cu^2+}$ and $\ce{SO4^2-}$. $\ce{Cu(OH)2}$, however, is not: $K_\mathrm{sp} = 2 \cdot ...
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Odd Magnetic Susceptibility Trend?

So I was recently looking at this website. http://www.fizika.si/magnetism/MagSusceptibilities.pdf It lists the susceptibility values for inorganic compounds, and I've noticed that the trends don't ...
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Why does some copper (I) compound show color? [duplicate]

As far as I know, if the d orbital of a d-block element is fulfilled, then there is no way for electrons to change the orbital and show color. But some of Copper (I) compounds do show color. How is ...
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Why tungsten does not have stable configuration? [duplicate]

Whenever there are 4 unpaired electrons in d-orbital, elements try to attain stable electronic configuration. For example copper. Electronic configuration of copper should be [Ar]3d4 4s2, but it ...
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2answers
171 views

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 ...
5
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2answers
95 views

Transition Metal Compounds

So I have a few dumb questions. I'm still in high school and am doing something on magnetic properties of transition metals. I'm facing a few roadblocks. 1) What're compounds like $\ce{CoBr2, CoCl2, ...
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2answers
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Odd Acidity Trend in Hexaaqua Metal Complexes

In the following link (three quarters down the page) it states that theoretically there should be a proportional relationship between the ionic radius and pKa of a hexaaqua metal complex (provided ...
5
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1answer
174 views

How to determine VSEPR shape from molecular orbital theory?

The molecule $\ce{[PdCl4]^2-}$ is diamagnetic. So since $\ce{Pd}$ is $\mathrm{d^8}$, and the oxidation number is $+2$, that means, there are two lone pairs, so the molecule is $\ce{AX4E2}$, making it ...
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1answer
72 views

General notation for one of the d-orbitals

What is the general notation to represent the d-orbital with $l=2$, $m_l=0$, i.e. the orbital normally referred to as $\mathrm{d}_{z^2}$. To elaborate more, this orbital can be ordered in various ways ...
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Reference request for properties of amorphous titanium carbide (a-TiC)

I assume through some side reaction I'm getting $\ce{TiC}$ in my $\ce{TiO2}$ samples after calcination and I need some basic information about the properties of amorphous $\ce{TiC}$. Is it ...
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0answers
44 views

Difference in color between the chromate and permanganate ions

As the title states, I'm wondering why the $\ce{[CrO4]^2-}$ and $\ce{[MnO4]-}$ ions display different colors in solution. Both of the metal ions have a $\mathrm{d}^0$ electron configuration, have the ...
4
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1answer
201 views

How can the intense color of potassium permanganate be explained with molecular orbital theory?

In the permanganate ion, manganese is in the $+7$ oxidation state, therefore it is a $\ce{d^0}$ ion. $\ce{d^0}$ and $\ce{d^1^0}$ ions don't absorb visible spectrum radiation because there are no ...
2
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1answer
98 views

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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2answers
815 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 ...
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Making elemental sulfur from pyrite FeS2

Has anyone done this or know of a good experiment that would allow someone to make elemental sulfur from $\ce{FeS2}$ (iron pyrite)?
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1answer
31 views

Predicting oxidation state of transition metal in chemical reaction

When predicting products of a chemical reaction, how would you determine what the oxidation state of the transition metal is? For example, $$\ce{Fe +Cl2->} ?$$ The product here is supposed to be ...
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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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1answer
72 views

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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1answer
171 views

Why do transition metals form particularly stable complexes?

The pre-transition metal ions can form complexes but the ligands are weakly bound unless they are multidentate and thus benefit from the chelate effect. For example, crown ethers and cryptands. ...
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2answers
59 views

Colorless nature of carbonyl complexes

Researching the coloration of transition metal complexes one day, I came across this reference on Wikipedia 1: I am not sure why this is so. Take $\ce{Mo(CO)_6}$, or any other carbonyl complex of ...
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0answers
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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 ...
2
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2answers
193 views

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

What I know: (1) Empty 3d orbitals are higher in energy than empty 4s orbitals (2) Aufbau Principle (electrons always go into an empty orbital with the lowest energy) (3) Partially/half/fully ...
0
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1answer
188 views

Anomalous configuration for Palladium?

The p block elements generally have the general valence she'll configuration as $$n\mathrm{p}^{1-6}\,n\mathrm{s}^{1-2}.$$ Expected electronic configuration for palladium is $$\ce{^46Pd} = ...
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Exceptions to the Madelung rule for electronic configurations

The electronic configuration of Platinum is [Xe] 4f14 5d9 6s1. and not [Xe] 4f14 5d10 6s0 or [Xe] 4f14 5d8 6s2. I see this question has already been answered, but here is what wikipedia says: ...
3
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1answer
647 views

Why does density decrease across the period 4 and 5 transition metals?

I know that density decreases across period 4 because the last two elements are liquids and gases which means that their densities are less but why are the densities increasing and then decreasing ...
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1answer
188 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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1answer
1k 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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2answers
619 views

Why is it that the least reactive metals are the best electrical conductors?

Silver, Gold and Platinum are amongst the best conductors of electricity, but also the amongst the most unreactive. Since electrical conductivity depends on the number of delocalized electrons (along ...
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2answers
236 views

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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2answers
335 views

Why Cr(2+) 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 getting oxidized will get a stable $d^5$ configuration and $\ce{Cr^{2+}}$ will get a $d^3$ configuration. ...
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1answer
9k views

Why are there peaks in electronegativities in d-block elements?

Looking at the Pauling electronegativities in the Periodic Table (below, from ChemWiki): Asides from the overall trend of increasing electronegativity across and up the Periodic Table (towards ...
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2answers
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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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1answer
77 views

Palladium Nanocube

What is the relative permittivity and relative permeability of a palladium nanocube? If I change the size of this $\ce{Pd}$ nanocube, will these values be changed or remain the same?
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1answer
37 views

Pb-based pigments and rhodizonate salts

In a previous question, I learned that we can detect lead with sodium / potassium rhodizonate, giving a nice purple color when reacting with pure (elemental?) lead. But in the paint, lead is ...