d & f Block Elements

Question 0

Zn Cd Hg are not typical d block elements because

Answer 0

They have completely filled d orbitals in their ground state as well da in their common oxidation state.

Question 1

d block includes the groups

Answer 1

3-12

Question 2

General E.C of d block elements is

Answer 2

(n-1)d^1-10 ns0-2

Question 3

Which transition metals do not have a typical metallic structure at normal temp

Answer 3

Zn Cd Hg Mn

Question 4

Trend of enthalpy of atomisation and mp in d block

Answer 4

Rises upto d5 and falls regularly as atomic number increases

Except anamolous Mn and Tc

Question 5

What is lanthanides contraction?

Answer 5

Filling of 4f electron before 5d results in a regular decrease in atomic radii

Hence, 4d & 5f series exhibit similar radii and properties

Question 6

The transition metal which does not show variable o.s

Answer 6

Sc

Question 7

Transition metals which exhibit o.s of +8

Answer 7

Rh and Os

Question 8

Why higher o.s are stable with O and F

Answer 8

Due to high oxidising power of F &O

Question 9

Tendency to form divalent cations decreases across the series because of

Answer 9

Increase in reduction potential from left to right

Question 10

Strongest oxidising agents in aq solutions are

Answer 10

Mn3+ and Co3+

Question 11

Frequency of light absorbed is determined by

Answer 11

Nature of ligand
Size of metal ion
Oxidation state of metal

Question 12

Colour may be due to

Answer 12

d-d transition
Charge transfer spectra
Eg:-(MnO4- is pink)
Polarisation
Eg:-(AgBr AgI)

Question 13

Transition metals show catalytic properties because of their ability to

Answer 13

Form complex compounds

Adopt multiple oxidation states

Question 14

Fe is used to catalyse

Answer 14

Haber process

Question 15

PdCl2 catalyses

Answer 15

Wacker process

Question 16

Adams catalyst is

Answer 16

Pt/PtO2

Question 17

Lowest melting point metals among transition metals belong to

Answer 17

Group 12

Question 18

Most abundant transition metal is

Answer 18

Iron

Question 19

All metals form ionic metal oxides except

Answer 19

Sc

Question 20

Nature of higher oxides is predominantly

Answer 20

Acidic

Question 21

Cr2O3 and V2O5 are

Answer 21

Amphoteric oxides

CrO is basic

Question 22

Chromite is

Answer 22

FeCr2O4

Question 23

Potassium dichromate is used in

Answer 23

Leather industry and in preparation of azo compounds

Question 24

Colour of sodium dichromate(Na2Cr2O7.2H2O) is

Answer 24

Orange Na2Cr2O7 is more soluble than K2Cr2O7

Question 25

CrO4- and Cr2O72- exist in eq at pH=?

Answer 25

4

Question 26

Commercially potassium permanganate is prepared by

Answer 26

Oxidative fusion of MnO2 followed by electrolytic oxidation of manganate

Question 27

CrO5 is stable only in

Answer 27

Ether or pyridine In aq solution it decomposes to dioxygen and Cr3+

Question 28

Chromyl chloride test of for

Answer 28

Presence of chloride ion

Question 29

Oxidation state of Mn in KMnO4 in acidic basic and neutral media are

Answer 29

Acid. +2 Base +6 Neutral +4

Question 30

Magnetic behaviour of permangnate ion is

Answer 30

Diamagnetic Green manganate ion is paramagnetic

Question 31

When ferrous chloride is added to potassium ferrocyanide there is formation of

Answer 31

Prussian blue

Question 32

How does atomic size vary in lanthanides

Answer 32

Decreases from La to Lu

Question 33

Most common o.s in lanthanides

Answer 33

+2 & +3 +4 is exhibited by Pr Nd Tb Dy in MO2 oxide

Question 34

Hardest lanthanides is

Answer 34

Sm(62)

Question 35

Trivalent lanthanide ions are coloured both in solid and liq state due to

Answer 35

Presence of f electrons

Question 36

Best Use of lanthanoid

Answer 36

Production of alloy Steel

Question 37

What is Mischmetal used for?

Answer 37

To form bullets ``` It contains a lanthanoid metal[95%] Iron[5%] and traces of S C Ca Al ```

Question 38

Mixed oxides of lanthanoids are used in

Answer 38

Petroleum cracking

Question 39

Which lanthanide has maximum paramagnetism in +3 state?

Answer 39

Gd

Question 40

Lawrencium has a half life of

Answer 40

3 min

Question 41

In which inner transition element electron is not added to the f orbital

Answer 41

Th

Question 42

How do actinoids react with acids and alkali

Answer 42

HCl reacts with all actinoids Most are slightly affected by HNO3 as formation of a protective oxide layer occurs But alkali have no action

Question 43

Actinoids are coloured due to

Answer 43

Charge transfer or f-f transition

Question 44

Lightest transition element is

Answer 44

Sc

Question 45

Densest transition element is

Answer 45

Os

Question 46

Verdigris is

Answer 46

Basic copper acetate | (CH3COO)2Cu.Cu(OH)2

Question 47

Gold is soluble in which transition metal?

Answer 47

He

Question 48

What is purple of Cassius ?

Answer 48

Colloidal gold | Very dil. gold chloride +SnCl2

Question 49

What is fulminating gold ?

Answer 49

Au(NH2)=NH

Question 50

Zn becomes malleable and ductile at

Answer 50

100c

Question 51

How do monovalent mercurous ions exist

Answer 51

As dimers

Question 52

Philosophers wool is

Answer 52

ZnO Also called zinc white or Chinese white It gives green mass in cobalt chloride test...turns yellow on heating white on cooling

Question 53

Calomel is

Answer 53

Hg2Cl2

Question 54

Corrosive sublimate is

Answer 54

HgCl2

Question 55

Vermillion is

Answer 55

Mercuric sulphide (HgS)

Question 56

Hg does not form amalgam with

Answer 56

Fe and Pt

Question 57

Pharaohs serpent is

Answer 57

Mercury fulminate (Hg(ONC)2) It is used as explosive

Question 58

Mixture of TiO2 and BaSO4 is called

Answer 58

Titanox

Question 59

Lithopone is

Answer 59

ZnS+BaSO4

Question 60

Nesslers reagent(K2[HgI4]) is used to detect

Answer 60

NH3