d block

Question 1

all transition elements forms metal oxides..except one element..who is that

Answer 1

scandium..its is ionic

Question 2

fajan’s rule

Answer 2

as oxidation state of metal oxides increases,ionic characcter of oxides decreases

Question 3

condition to form alloy

Answer 3

their radii should be within 15%
ie, should be of similar metallic radii

Question 4

properties of alloys

Answer 4

*very hot
*high mp
*high resistance to corossion

Question 5

stainless steel is the alloy of

Answer 5

Fe+Cr+Ni+C

Question 6

ferrous alloy/steel alloy made up of

Answer 6

Cr,Ni,Mn,V,Mo,W with steel

Question 7

measuring tape and pendulum are made using

Answer 7

nickel steel

Question 8

cutting tools and crushing machines are made up of

Answer 8

chrome steel

Question 9

transition metal ions forms stable complexes due to

Answer 9

*small size
*high charge
*high charge/size (charge density)
*availability of vacant d orbitals

Question 10

ferric is more stable than ferrrous
[fe(cn)6]^3- > [fe(cn)6]^4-
why?

Answer 10

fe^3+ have high e/m ratio

Question 11

why interstetial compunds are non stochiometric?

Answer 11

coz the bonding b/w metal atoms and non metal atoms are neither ionic nor covalent

Question 12

hydride gap

Answer 12

the void of grp 7,8,9 is very small compared to hydride ion(H^-) (2 e,1 p)
hydride ion cant be in these voids.so they cannot form hydride

Question 13

interstetial compounds are chemically inert.
true/false

Answer 13

true

Question 14

colourless ions

Answer 14

Fe(3+), Y(3+), Al(3+),Ac(3+),Zn(2+)

Question 15

a)philosopheres wool/white Zn?
b)white vitreol?

Answer 15

a)Zno
b)ZnSO(4).7H(2)0

Question 16

amount of energy released during the exhange of electrons of same spin in degenerate orbitals….

Answer 16

exchange energy(exothermic)

Question 17

pairing energy

Answer 17

amt of energy req to pair up electrons in the same orbital.(endothermic)

Question 18

haemoglobin is a complex of

Answer 18

Fe2+

Question 19

german silver is an alloy of

Answer 19

Cu+Zn+Ni

Question 20

lanthanide contraction relates to atomic radii as well as M(3+) radii
true/false

Answer 20

true

Question 21

most common oxidation state among lanthanides

Answer 21

+3

Question 22

Ln(111) compounds are generally colourless.
true/false

Answer 22

false.
most of the trivalent lanthanoid compunds except of La(3+) and Lu(3+) are coloured both in aqueous and solid solution.

Question 23

lanthanum is grouped with f block elements because

Answer 23

the properties of lanthanum are very similar to 4f series

Question 24

transition metals present in misch metal

Answer 24

95% rare eartth metals
5% Fe
traces of S,c,Ca,Al

Question 25

which is the trasition metal as per the ground state?

Answer 25

Au

Question 26

negligible screening effect of f orbitals are termed as

Answer 26

lanthanoid contraction

Question 27

the maximum oxidation state exhibited by actinide ions are

Answer 27

+4

Question 28

actinoid contraction is however greater than lanthanoids.due to

Answer 28

there is poor shielding by 5f electrons

Question 29

Cr-O-Cr bond angle of dichromate ion ..

Answer 29

179 pm

Question 30

6 Cr-O bonds in dichromate ion with bond angle

Answer 30

163pm

Question 31

mixed oxides formed by elements of 3d series of d block is

Answer 31

Cr,Mn,Fe

Question 32

the difference b/w melting point pf samarium and the upperr value of mp range of lanthanoids is

Answer 32

423.
mp of Sm=1623K;
range:1000-1200K