Nitrogen Group Flashcards
Mention the nature of elements in Nitrogen group.
N - Non metal
P - Non metal
As - Metalloid
Sb - Metalloid
Bi - Metal
At. Radius order
N<P<As<Sb<Bi
Here N to P there is a considerable increase in size.
Ionisation energy order
N>P>As>Sb>Bi
Electronegativity order
N>P>As>Sb=Bi
BP order
N<P<As<Sb>Bi</Sb>
MP order
N<P<As>Sb>Bi</As>
Mention important physical properties of nitrogen.
1) All elements in the Nitrogen group are polyatomic except N (diatomic).
2) Except N all other elements show allotropy.
State common oxidation states in the Nitrogen group.
Tendency to show -3 oxidation state decreases down the group.
Tendency to +3 oxidation state increases down the group.
Tendency to show +5 oxidation state decreases down the group.
Mention anomalous properties of Nitrogen.
1)N - Small size, high ionisation energy, high electronegativity, no d orbitals present.
2)N shows pπ-pπ multiple bond with itself or other small sized elements.
3)Catenation is weak in Nitrogen
Show the reactivity of nitrogen group elements with hydrogen.
NH3>PH3>AsH3>SbH3>BiH3
Basicity, stability increases towards left
Reducing nature increases towards right
Show nature of oxides of N group elements.
N2O3>P2O3>As2O3>Sb2O3>Bi2O3
N2O3 and P2O3 are acidic
As2O3 and Sb2O3 are amphoteric
Bi2O3 is basic
Down the group acidic character decreases.
Mention commercial preparation of Nitrogen.
Liquifaction and fractional distillation of air
(Liq.N2 + O2) - Mixture
Liq.N2 - 77.2K
Liq.O2 - 90K
These are B.P.
Mention laboratory preparation of N2.
NH4NO2 ➡️ N2 + NaCl + H2O
(NO, HNO3 is also formed here) - Removed by passing through aq. Sol of H2SO4 containing K2Cr2O7
(NH4)2Cr2O7 ➡️ N2 + Cr2O3 + H2O
NaN3 ➡️ Pure N2
Ba(N3)2 ➡️ Pure N2
Mention physical properties of N2.
1) It is inert because it contains high bond energy of N triple bond N.
2) When Temp. Increases then reactivity also increases.
3) N2 + Metal ➡️ ionic nitride
Ex. Li + N2 ➡️ Li3N
Mg + N2 ➡️ Mg3N2
N2 + non metal ➡️ covalent nitride
Show preparation of NH3.
∆
NH2CONH2 + H2O ➡️ (NH4)2CO3 ➡️ NH3 + H2O + CO2
Show small scale preparation of NH3.
NH4Cl + Ca(OH)2 ➡️ CaCl2 + NH4OH
(NH4)2SO4 + NaOH ➡️ Na2SO4 + NH4OH
Show large scale preparation of NH3.
Haber’s Process
N2 + 3H2 ➡️ 2NH3
Reaction with Acid.
NH3 + HCl ➡️ NH4Cl
NH3 + H2SO4 ➡️ (NH4)2SO4
Reaction of NH4OH with metal salt.
NH4OH + ZnSO4 ➡️ Zn(OH)2 + (NH4)2SO4
NH4OH + FeCl3 ➡️ Fe(OH)3 + NH4Cl
Show reactions where NH3 acts as Lewis base.
Cu+2 + NH3 ➡️ [Cu(NH3)4]+2SO4
AgCl + NH3 ➡️ [Ag(NH3)2]+Cl
Show preparation of nitrogen oxides with +1,+2 and +3 oxidation states.
1) NH4NO2 ➡️ N2 + H2O
NH4NO3 ➡️ N2O + H2O
2) N2 + O2 ➡️ 2NO
NaNO2 + FeSO4 + H2SO4 ➡️ Fe2(SO4)3 + NaHSO4 + NO + H2O
3) NO + N2O4 ➡️ N2O3
Show preparation of nitrogen oxides with +4 again +4 and +5 oxidation states.
1) Pb(NO3)2 ➡️ PbO + NO2 + O2
Cool
2) NO2 ➡️ N2O4
Heat
3) HNO3 + P4O10 ➡️ N2O5 + H2O
HNO3 preparation.
KNO3 + H2SO4 ➡️ HNO3 + K2SO4
NaNO3 + H2SO4 ➡️ Na2SO4 + HNO3
Large scale preparation of HNO3 - Ostwald process.
NH3 + O2 ➡️ NO + H2O
NO + O2 ➡️ NO2 (brown)
NO2 + H2O ➡️ HNO3 + NO
Show the oxidising nature of HNO3.
Conc. HNO3 + Any metal ➡️ NO2 + H2O + Metal nitrate
Dil.HNO3 + Pb,Cu,Ag,Hg ➡️ NO + H2O + Metal nitrate
Dil.HNO3 + Fe,Zn ➡️ N2O + H2O + Metal nitrate
Dil.HNO3 + Sn ➡️ NH4NO3 + Metal nitrate
Very Dil.HNO3 + Mg,Mn ➡️ H2 + Metal nitrate
Very Dil.HNO3 + Fe,Zn,Sn ➡️ NH4NO3 + Metal nitrate
How the brown ring complex was made.
1) Dilute ferrous sulphate is added to an aqueous solution containing nitrate ion.
2) Now carefully adding Conc.H2SO4 along the walls of the container.
3) Brown ring forms at the interface of solution.
NO3 + FeSO4 + H+ ➡️ Fe+3 + NO + H2O
NO + [Fe(H2O)6]+2 ➡️ [Fe(H2O)5NO]+2
(Brown ring complex)
Tell about White P.
Tetrahedral
Less stable (angle strain)
P4 + O2 ➡️ P4O10 (white dense fumes)
White and translucent waxy solid
Poisonous and insoluble in water and soluble in CS2
Glow in dark
Dissolves in NaOH
P4 + NaOH ➡️ NaH2PO2 + PH3
Tell about Red P.
Heating white P at 573K in inert atmosphere for several days
Iron grey lustre
Odourless, non poisonous, insoluble in water and CS2
Less reactive than white P
Do not glow in dark
Tell about Black P.
Red P is heated under high pressure ➡️ Black P
Alpha black - Red P is heated in a sealed tube at 803K.
Do not oxidise in air
Beta black - White P heated at 473 K under very high pressure.
Doesn’t burn up to 673K
Black P has layered structure like graphite but non planar
Mention preparation of PH3.
Ca3P2 + H2O/Dil.HCl ➡️ Ca(OH)2 or CaCl2 + PH3
Laboratory preparation
White P + NaOH ➡️ PH3 + NaH2PO2
PH3 - Pure form ➡️ non inflammable, but becomes inflammable when dissolved in peroxide of P2H4 or P4 vapours.
How to purify PH3.
PH3 + HI ➡️ PH4I
PH4I + KOH ➡️ PH3 + H2O + KI
Describe the nature of PH3.
Colourless, rotten fish smell, highly poisonous.
Explodes in presence of oxidising agent
Show reactions of PCl3.
White P + Cl2 ➡️ PCl3
Or
P4 + Cl2 ➡️ PCl3
White P + Thionyl Chloride
P4 + SOCl2 ➡️ PCl3 + SO2 + S2Cl2
PCl3 + H2O ➡️ H3PO3 + HCl
CH3COOH + PCl3 ➡️ CH3COCl + H3PO3
C2H5OH + PCl3 ➡️ C2H5Cl + H3PO3
Show reactions of PCl5.
P4 + Cl2(excess) ➡️ PCl5
P4 + SO2Cl2 ➡️ PCl5 + SO2
PCl5 + H2O ➡️ HCl + POCl3
POCl3 + H2O ➡️ H3PO3 + HCl
CH3COOH + PCl5 ➡️ CH3COCl + POCl3 + HCl
C2H5OH + PCl5 ➡️ C2H5Cl + POCl3 + HCl
Show oxyacids of P.
H3PO2 Hypophosphorous acid
H3PO3 Ortho Phosphorous acid
H4P2O5 Pyro phosphorous acid
H4P2O6 Hypophosphoric acid
H3PO4 Orthophosphoric acid
H4P2O7 Pyrophosphoric acid
(HPO3)n Metaphosphoric acid - Can be cyclic (n=3) or poly metaphosphoric acid.
