d & f Block Elements Flashcards
Zn Cd Hg are not typical d block elements because
They have completely filled d orbitals in their ground state as well da in their common oxidation state.
d block includes the groups
3-12
General E.C of d block elements is
(n-1)d^1-10 ns0-2
Which transition metals do not have a typical metallic structure at normal temp
Zn Cd Hg Mn
Trend of enthalpy of atomisation and mp in d block
Rises upto d5 and falls regularly as atomic number increases
Except anamolous Mn and Tc
What is lanthanides contraction?
Filling of 4f electron before 5d results in a regular decrease in atomic radii
Hence, 4d & 5f series exhibit similar radii and properties
The transition metal which does not show variable o.s
Sc
Transition metals which exhibit o.s of +8
Rh and Os
Why higher o.s are stable with O and F
Due to high oxidising power of F &O
Tendency to form divalent cations decreases across the series because of
Increase in reduction potential from left to right
Strongest oxidising agents in aq solutions are
Mn3+ and Co3+
Frequency of light absorbed is determined by
Nature of ligand
Size of metal ion
Oxidation state of metal
Colour may be due to
d-d transition Charge transfer spectra Eg:-(MnO4- is pink) Polarisation Eg:-(AgBr AgI)
Transition metals show catalytic properties because of their ability to
Form complex compounds
Adopt multiple oxidation states
Fe is used to catalyse
Haber process
PdCl2 catalyses
Wacker process
Adams catalyst is
Pt/PtO2
Lowest melting point metals among transition metals belong to
Group 12
Most abundant transition metal is
Iron
All metals form ionic metal oxides except
Sc
Nature of higher oxides is predominantly
Acidic
Cr2O3 and V2O5 are
Amphoteric oxides
CrO is basic
Chromite is
FeCr2O4
Potassium dichromate is used in
Leather industry and in preparation of azo compounds
Colour of sodium dichromate(Na2Cr2O7.2H2O) is
Orange
Na2Cr2O7 is more soluble than K2Cr2O7
CrO4- and Cr2O72- exist in eq at pH=?
4
Commercially potassium permanganate is prepared by
Oxidative fusion of MnO2 followed by electrolytic oxidation of manganate
CrO5 is stable only in
Ether or pyridine
In aq solution it decomposes to dioxygen and Cr3+
Chromyl chloride test of for
Presence of chloride ion
Oxidation state of Mn in KMnO4 in acidic basic and neutral media are
Acid. +2
Base +6
Neutral +4
Magnetic behaviour of permangnate ion is
Diamagnetic
Green manganate ion is paramagnetic
When ferrous chloride is added to potassium ferrocyanide there is formation of
Prussian blue
How does atomic size vary in lanthanides
Decreases from La to Lu
Most common o.s in lanthanides
+2 & +3
+4 is exhibited by Pr Nd Tb Dy in MO2 oxide
Hardest lanthanides is
Sm(62)
Trivalent lanthanide ions are coloured both in solid and liq state due to
Presence of f electrons
Best Use of lanthanoid
Production of alloy Steel
What is Mischmetal used for?
To form bullets
It contains a lanthanoid metal[95%] Iron[5%] and traces of S C Ca Al
Mixed oxides of lanthanoids are used in
Petroleum cracking
Which lanthanide has maximum paramagnetism in +3 state?
Gd
Lawrencium has a half life of
3 min
In which inner transition element electron is not added to the f orbital
Th
How do actinoids react with acids and alkali
HCl reacts with all actinoids
Most are slightly affected by HNO3 as formation of a protective oxide layer occurs
But alkali have no action
Actinoids are coloured due to
Charge transfer or f-f transition
Lightest transition element is
Sc
Densest transition element is
Os
Verdigris is
Basic copper acetate
(CH3COO)2Cu.Cu(OH)2
Gold is soluble in which transition metal?
He
What is purple of Cassius ?
Colloidal gold
Very dil. gold chloride +SnCl2
What is fulminating gold ?
Au(NH2)=NH
Zn becomes malleable and ductile at
100c
How do monovalent mercurous ions exist
As dimers
Philosophers wool is
ZnO
Also called zinc white or Chinese white
It gives green mass in cobalt chloride test…turns yellow on heating white on cooling
Calomel is
Hg2Cl2
Corrosive sublimate is
HgCl2
Vermillion is
Mercuric sulphide (HgS)
Hg does not form amalgam with
Fe and Pt
Pharaohs serpent is
Mercury fulminate (Hg(ONC)2)
It is used as explosive
Mixture of TiO2 and BaSO4 is called
Titanox
Lithopone is
ZnS+BaSO4
Nesslers reagent(K2[HgI4]) is used to detect
NH3
