p block (n fam)

Question 1

NITROGEN FAMILY

Answer 1

nitrogen
phosphorous
arsenic
antimony
bismuth
moscovium

Question 2

this elemnts are known as…..
and its compunds are known as…

Answer 2

pnicogens
pnicanides

Question 3

moscovium is a synthetic,extremely radioactive,trasactinide element with very short….

Answer 3

half life

Question 4

nitrogen occur as ……. gas

Answer 4

diatomic

Question 5

it constitutes ….. % of atmosphere

Answer 5

78

Question 6

33rd most abundant on earths crust

Answer 6

nitrogen

Question 7

nitrogen mainly occur as nitrates.Eg

Answer 7

Chile saltpetre- NaNO3
Indian saltpetre - KNO3

Question 8

essential constituent of protiens,amino acids,nucleic acids

Answer 8

nitrogen

Question 9

phosphorus is very reactive element hence

Answer 9

it donot occur in free in nature

Question 10

11 most abundunt in earth crust

Answer 10

phosphorous

Question 11

phosphorus occur in apetite minerals

Answer 11

3Ca3(PO4)2.CaX2
X=F,Cl,OH
ie, fluroapetite,chloroapetite,hydroxyapetite

Question 12

As,Sb,Bi are mainly occur as

Answer 12

sulphide minerals
[mispickel,stibnite,realgar,orpiment,bismuth galnce,bismuthinite,bismite]

Question 13

IE order

Answer 13

N>P>As>Sb>Bi

Question 14

order of first,second,thrid IE

Answer 14

IE1<IE2<IE3

Question 15

EN

Answer 15

elecctronegative than grp 14..doen the grp gradual decrease

Question 16

metallic char

Answer 16

less than corresponding 14th grp..however metallic char increases down the grp

Question 17

why met.char is less than corresponding 14th

Answer 17

due to increased nuclear charge and higher EN

Question 18

why met.chr increases down the grp

Answer 18

en decreases down the grp.valence electron are lost more readily.
N & P are non metals
As & Sb are metalloids
Bi typical metal

Question 19

melting point increases down the grp N to As due to

Answer 19

increase in at.size

Question 20

why melting point of Sb and Bi decreases

Answer 20

due to inert pair effect,their tendency is to form three covalent bonds instead of 5.this results in weakening of attraction among atoms.

Question 21

bismuth has weaker interatomic forces than antimony hence melting point

Answer 21

is low

Question 22

density

Answer 22

increses down the grp

Question 23

allotropy

Answer 23

exccept N and Bi all have allotropes
phosphorus(3)-red,white,black
As and Sb (2)-yellow,grey

Question 24

why negative oxdn state

Answer 24

since they have 5 electran as valence only needed3 electrons to attain noble gas configuration.
hence nitrogne forms nitrides (N3-) with highly elecctro[psitive metals(Mg3N2,Ca3N2)
other elements forms coalent compound(Ca3P2,Na3As,Zn3Sb2,Mg3Bi2)

Question 25

besides -3 ,N and P exhibit -2 oxdn state in...

Answer 25

hydarzine,diphoshpine

Question 26

N also shows -1 in....... but phosphorus does not

Answer 26

hydroxylamine

Question 27

why PF5,PCl5,SbF5 and BiF5 are covalent

Answer 27

due to large amount of energy needed to lose 5 valence electrons,M+5 ions are not formed

Question 28

but in +3 oxn state these elements forms both ionic and covalent compounds

Answer 28

true

Question 29

cov char decreases in the order

Answer 29

N>P>As>Sb>Bi

Question 30

nitrogen because of samll size,high en,strong tendancy to form ppi-ppi multiple bonds shows oxn no. -3 to +5

Answer 30

NH3= -3 NH2NH2= -2 NH2OH= -1 N2= 0 N2O=+1 NO= +2 N2O3= +3 NO2 OR NN2O4= +4 N2O5= +5

Question 31

max covalency shown by nitrigen due to lone paiir

Answer 31

4

Question 32

all the oxdn state of nitrogen from +1 to +4 exhibit....... in acidic medium

Answer 32

disproportionation

Question 33

phosphoru is all oxdn state from -3 to +5 shows

Answer 33

disproportionation in both acidic and basic medium

Question 34

due to inert pair effecct,the stability of +3 ..... feom As to BBI

Answer 34

increases

Question 35

melting point orderr of their hydrides

Answer 35

NSAP N>Sb>As>P

Question 36

boiling point order of their hydrides

Answer 36

BSNAP B>Sb>N>A>P

Question 37

thermal stability

Answer 37

as size increases M-H bond strength decreases,stability decreases

Question 38

reducing char

Answer 38

increases down the grp

Question 39

basaic nature

Answer 39

decreases down the grp hydrides are lewis bases (have a lone pair of electrons on the central atom)

Question 40

formation of oxides

Answer 40

E2O3,E2O5

Question 41

how oxn state and oxidic strngth relatedhigher the oxn state of the element greater is its acidic strngth

Question 42

reactn towards halogens

Answer 42

forms trihalides and pentahalides

Question 43

why N does not form pentahalides

Answer 43

due to absence of d orbitals

Question 44

as the size of the halogen grp increases phosphorus-halogen bond strngth decreases due to

Answer 44

steric hindrance

Question 45

catenation

Answer 45

phosphorus has the max tendency for catenation. ntrogen has only a little tendency due to N-N single bond is very weak [repulsion of lone pair]

Question 46

N2 is inert due to

Answer 46

presence of triple bond,bond length is very ssmall.BDE is very small

Question 47

why nitrogen cant form dpi ppi bonds

Answer 47

absence of d orbitals

Question 48

nature of trihalides

Answer 48

except nf3 other trihalides of nitrogen unstable and explosive.other trihalides are stable

Question 49

white phosphorus

Answer 49

discreet units of P4 more reactive volatile dissolves in CS2 on contact with air it reats with O2 to give chemiluminesccence

Question 50

red phosphorus

Answer 50

linear chain of P4 less reactive less volatile insoluble in CS2 doesnt give chemiluminiscence

Question 51

black phos[horus

Answer 51

most thermodynamically stable allotrope

Question 52

prprn of allotropes

Answer 52

white P when heated with 573K gives red P,its is heated at 803K gives alpha black otherwise heated at 473 K at high pr. gives beta black