· Web view2017-03-28 · P – Ca9(PO4)6.CX2 (X = F2Cl2, OH) eg(fluorapatite Ca9(PO4)6.CaF2) It...
Transcript of · Web view2017-03-28 · P – Ca9(PO4)6.CX2 (X = F2Cl2, OH) eg(fluorapatite Ca9(PO4)6.CaF2) It...
UNIT- 7 P – BLOCK ELEMENTS
Properties at Glance
Properties Group. 15 Group. 16 Group. 17 Group. 18Elements N, P, As, Sb, Bi
(P nicogens)O, S, Se, Te, Po
(Chalogens)F, Cl, Br, I, At
(Halogens)He, Ne, Ar,
Kr, XeElectronic
configurationns2, np3 ns2, np4 ns2, np5 ns2, np6
Occurance Atmosphere has 78% N2 in earth
crust is present as NaNO3, KNO3, it is also in proteins
in plants and animals.
P – Ca9(PO4)6.CX2
(X = F2Cl2, OH)
eg(fluorapatite Ca9(PO4)6.CaF2)
It is present in bones and living
cells, Phosphoprotien is in milk and eggs.
As,Sb, Bi are found in Sulphide
minerals.
O – atmosphere - 21%
Earth crust – 46.6%S – exists as
sulphatesEg. CaSO4.2H2O,
MgSO4.7H2O, organic minerals like eggs, proteins, garlic,
hair, wool, contain sulphur.
Se, Te are found as metal selenides and
tellurides in sulphide ores.
Po – obtained by decay of Th and U
minerals.
F – as CaF2, Na3AlF6, 3Ca(PO4)2.CaF2
Small quantities are present in soil, river –
H2O, plants, bones and teeth.
Sea – H2O has Cl-, Br-, I- of Na+, K+,
Mg2+, Ca2+.
Certain marine life contain I2, various sea
weeds and chile saltpetre has has I2.
Sea weed – 5% I2Chile saltpeter - 0.2%
NaOI3
(iodate)
Ar – 1%He, Ne found in radioactive
minerals, pitchblende, monazite, cleveite.
He – main source
natural gas
Group-15N-70,P-110,
As,121 ,Sb-141 , Bi-148
As - Bi - a small increase is seen due to presence of completely
filled d/f orbitals.
It is much higher than gp.14. I.E increases down the gp due to
half-filled stable configurations.
It decreases down the group because metallic character decreases down
the group.
Less metallic than gp.14 and
metallic character increases down
the group.N, P - non-metals
As, Sb - metalloidsBi - metal.
N, Bi - no allotropes
P - red, white, black
As, Sb - yellow, gray
Group-16O-66, S-104, Se-117,
Te-137, Po-230
I.E1 < I.E2 of gp 15.
O has highest EN, (next to F).
gp.16 elements have high negative gain
enthalpy because of its small size.
S, O - non-metalSe, Te - metalloids
Po - metallic
O - O2, O3
Se - 8 allotropic forms, grey.Se conducts electricity
Te - 1 formPo - 2 forms.
Group-17F-64, Cl-99, Br-114,
I-133
I.E are very high. They have little
tendency to loose electrons.
X have maximum electron gain
enthalpy because they need only one
electron to complete the noble gas configuration.
X have very high ENF - most electro
negative compound.
All are non metals. Only I shows metallic
lusture.
Group-18He-120, Ne-160, Ar-190,Kr-200,Xe-220
Highest I.E in their respective period due to stable electronic configuration Electron gain enthalpy is positive because of noble gas configuration.
All are non-metals.
PropertiesAtomic radius
(Covalent radius in pm)
Ionization enthalpy
Electro negativity
(EN)
& electron gain enthalpy
Metallic character
Allotropy
Properties
Oxidation state
Hydrides
Oxides
Group-15
N(-3) Mg3N2
-2 NH2NH2
-1 NH2OHP(-3) Ca3P2
(-2) P2H4
all elements show +3 to +5
oxidation state.Down the gp +5
state stability decreases.
(Inert pair effect)
MH3
1. Stability decreases down
the gp.2. reducing character
decreases down the gp.
3. Basicity decreases down
th gp.
E2O3, E2O5
(more acidic)N2O3, P2O3 - acids
As, Sb oxides - amphoteric
Bi oxide - basic.
Group-15
Group-16
O - -2, -1, +2S, Se, Te, Po - +4,
+6, +2.
H2E (E- O, S, Se, Te)1. Acidic character
increases from H2O - H2Te
2. Stability decreases from H2O - H2Te.
3. except H2O all are good reducing agent,
H2Te - best.
EO2, EO3
SO2, O3 - gasesSeO2 - solid
Reducing property decreases from
SO3 - TeO2
(Oxidising agent)EO3 - SeO3, TeO3.
Group-17
F - 0nly -1Other X - -1, +1, +3,
+5, +7some X show +4 and
+6.
HXAcidic strength
HF < HCl < HBr < HI
Dissociation enthalpyHF > HCl > HBr >
HI
OF2, O2F2
Stable at 298KCl, Br, I form oxides
i range +1 to +7Stability of oxides-
I > Cl > BrCl2O, ClO2, Cl2O6,
Cl2O7 -highly reactive
oxidising agent and tend to explode.ClO2 - bleaching
agent
Br2O, BrO2, BrO3.
Group-18
----
----
XeO3
Properties
Halides
Reactivity towards metals
EX3, EX5
NX3 cannot be formed because of absence of d - orbital in case of N, Only NF3 is stable. All EX3
are covalent, except BiF3.
CaN2, Ca3P2
Na3As2, Zn3Sb2
o.s.(-3)
Group-16
EX6, EX4, EX2
(gases)SF6 - highly stableSF4(g), SeF4(lq),
TeF4(s)All elements except Se form dichlorides/
dibromides. Monohalides are
dimeric(S2F2, S2Cl2, S2Br2)
2Se2Cl2 - SeCl4 + 3Se(disproportionation
reaction)
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Group-17
XX2, XX3, XX5, XX7 - Inter halogen compounds
highly reactive.
Ionic characterMF > MCl > MBr >
MIIf M exhibits more oxidation, higher oxidation state
halides are covalent.
Group-18
XeF2, XeF4, XeF6, XeOF4,
XeO2F2
---
Equations at a glance
(1) (NH4)2Cr2O7 → N2 + 4H2O + Cr2O3 (2) Ba(N3)2 → Ba + 3N2
(3) NH2CONH2 + 2H2O → (NH4)2CO3↔2NH3+H2O+CO2
(4) 2NH4Cl + Ca(OH)2 → 2NH3 + 2H2O + CaCl2(5) (NH4)2SO4 + 2NaOH → 2NH3 + 2H2O + Na2SO4
(6) 2FeCl3 + 3NH4OH → Fe2O3.XH2O + 3NH4Cl (7) ZnSO4 + 2NH4OH →Zn(OH)2 + (NH4)2SO4
(8) 4H3PO3 → 3H3PO4 + PH3
(9) 4AgNO3 + 2H2O + H3PO2 → 4Ag + 4HNO3 + H3PO4
(10) 2Se2Cl2 → SeCl4 + 3Se (11) 2Ag2O → 4Ag + O2
(12) 2HgO → 2Hg + O2
(13) 2H2O2 → 2H2O + O2
(14) 2ZnS + 3O2 → 2ZnO + 2SO2
(15) Al2O3 + 6HCl +9H2O → 2[Al(H2O)6]3+ + 6Cl¯ (16) Al2O3 + 6NaOH + 3H2O → 2Na3[Al(OH)6] (17) 2I¯ + H2O + O3 → 2OH¯ + I2 +O2
(18) NO +O3 → NO2 + O2
(19) 4FeS2 + 11O2 → 2Fe2O3 + 8SO2
(20) 2NaOH +SO2 → Na2SO3 + H2O (21) Na2SO3 + H2O + SO2 → 2NaHSO3
(22) SO2 + Cl2 → SO2Cl2 (23) 2Fe2+ +SO2 +2H2O → 2Fe + SO4 +4H (24) 5SO2 + 2MnO4-- + 2H2O → 5SO42- + 4H+ + 2Mn2+
(25) F2 + 2X¯ →2F¯ + X2 (X=Cl,Br,I) (26) 2F2 +2H2O→ 4H+ + 4F- +O2
(27) X2 + H2O → HX + HOX (28) 4I- + 4H+ + O2 → 2I2 + 2H2O (29) 4NaCl + MnO2 + 4H2SO4 → MnCl2 + 4NaHSO4 + 2H2O + Cl2 (30) 2KMnO4 + 16HCl → 2KCl + 2MnCl2 + 8H2O + 5Cl2 (31) 4HCl + O2 → 2Cl2 + 2H2O (DEACON’S PROCESS) (32) 2Al + 3Cl2 → 2AlCl3
(33) C10H16 + 8Cl2 → 16HCl + 10C (34) 8NH3 +3Cl2 → 6NH4Cl +N2
(35) NH3 + 3Cl2 → NCl3 + 3HCl (36) 2NaOH + Cl2 → NaCl + NaOCl +H2O (37) 6NaOH + 3Cl2 → 5NaCl + NaClO3 + 3H2O (38) 2Ca(OH)2 + 2Cl2 → Ca(OCl)2 + CaCl2 + 2H2O (39) 2FeSO4 + H2SO4 + Cl2→ Fe2(SO4)3 + 2HCl (40) Na2SO3 + Cl2 + H2O → Na2SO4 + 2HCl (41) SO2 + 2H2O + Cl2 → H2SO4 + 2HCl
(42) I2 + 6H2O + 5Cl2 → 2HIO3 + 10HCl (43) Cl2 + H2O → 2HCl +O (44) Cl2 + F2 → 2ClF (45) I2 + Cl2 → 2ICl (46) XX’ + H2O → HX’+HOX (47) Xe + F2 → XeF2
(48) XeF4 + O2F2 → XeF6 + O2 (49) 2XeF2 + 2H2O → 2Xe + 4 HF +O2
(50) XeF2 + PF5 → [XeF]+ [PF6]¯ (51) XeF4 + SbF5 → [XeF3]+ [SbF6]¯ (52) XeF6 + MF+ → M [XeF7]¯ (M-Na, K,Rb or Cs) (53) 6XeF4 + 12H2O → 4Xe + 2XeO3 + 24HF + 3O2
(54) XeF6 + 3H2O → XeO3 + 6HF (55) Xe F6 +H2O → XeOF4 + 2HF (56) XeF6 + 2H2O → XeO2F4 + 4HF
Structures Of Compounds
1) NH3
2) White Phosphorus
3) Red Phosphorus
4) PCl3
5) PCl5
6)O3
7) S6
8) S8
9) SO2
10) HOClO
11) HOCl
12) HOClO2
13) HOClO3
14) BrF3
15) XeF2
16) XeF4
17) XeFO4
18) XeF6
19) XeO3
20) H4P2O7
21) H3PO3
22) H3PO2
23) H2SO3
24) H2SO4
25) H2S2O8
26) H2S2O7
27) N2O
28) NO
29) N2O4
30) NO2
31)N2O5
32) ICl4
33) IBr2 - 34)
BrO-3
Some important gases
S.no Gas Laboratory Preparation Properties Uses
1. N2 NH4Cl + NaNO2 → N2 + 2H2O+ NaCl Colourless, odourless, tasteless, non – toxic ,inert gas ∆6Li + N2→2Li3N
In manufacture of NH3, to provide inert atmosphere in industries.
2. O2 ∆2KClO3 →2KCl + 3O2 MnO2
Colourless, odourless, low solubility in water reacts with almost all metal & non-metal.
Used in respiration & combustion oxygen cylinders are used in hospitals.
3. O3 Electric discharge 3O2→2O3
Pale blue lq., dark blue lq., violet solid, strong oxidizing- agentNO + O3→ NO2 + O2
As germicide, disinfectant & for sterilizing H2O.
4. SO2 S + O2→SO2
2- SO3 +2H+→H2O + SO2
4FeS2 + 11O2→2Fe2O3 + 8SO2
Colourless , pungent smelling gas, highly soluble in H2O
in refining sugar in bleaching wool
5. Cl2 MnO2 + 4HCl → MnCl2 + Cl2 + 2H2O Greenish yellow gas, suffocating odour reacts with metal & non-metal to form chlorides
For bleaching wood pulp in manufacture of dyes
SOME IMPORTANT ACIDS
Prep.:- Ostwald process
NaNO3 + H2SO4 → NaHSO4 + HNO3
Pt/Rh4NH3 + 5O2 → 4NO + 6H2O condition : 500 K/9 bar
2NO2 + O2↔2NO2
3NO2 + H2O → 2HNO3 +NO
3Cu + 8HNO3(dil.) → 3Cu(NO3)2 + 2NO + 4H2O
Cu + 4HNO3(conc.) → Cu(NO3)2 + 2NO2 + 2H2O
I2 + 10HNO3 → 2HIO3 + 10NO2 + 4H2O
USE:- (HNO3) In manufacture of NH4NO3 for fertilizer, etching of metals.
H2SO4
Contact process
S + O2 → SO2
V2O5
SO2+ O2 → SO3
SO3 + H2SO4 →H2S2O7
H2S2O7 + H2O → 2H2SO4
Colourless dense lq, low volatility, strong affinity for H2O, strong oxidizing agent.Cu + 2H2SO4(conc.) → CuSO4 + SO2 + 2H2O
C + 2H2SO4 → CO2 + 2SO2 + 2H2O
(H2SO4)
In paint, dye, medicine, fertilizer etc. industries.
HCl
NaCl + H2SO4 →NaSO4 + HCl
Colourless, pungent smelling gas easily liquefied.
NH3 + HCl → NH4ClNa2CO3 + 2HCl → 2NaCl + H2O + CO2
3 : 1HCl HNO3
↑Is called aqua regia.
(HCl)
In manufacture of Cl2, NH4Cl, glucose.
COMPARISION OF PHOSPHINE WITH AMMONIA
S.No
Property Ammonia Phosphine
Resemblances
(i) Formula NH3 PH3
(ii) Colour & state
Colourless gas. Colourless gas.
(iii) Combustion Combustible in the presence of oxygen.
Combustible in the presence of oxygen.
(iv) Reaction with chlorine
Reacts with chlorine to form NCl3.NH3+3Cl2àNCl3+3HCl
Reacts with chlorine to form PCl3.PH3+3Cl2àPCl3+3HCl
(v) Reaction with halogen acids
Forms ammonium halides.NH3+HXàNH4XNH3+HClàNH4Cl
Forms phosphonium halides.PH3+HXàPH4XPH3+HClàPH4Cl
(vi) Reaction with Lewis acids
Forms addition compounds with Lewis acids(e.g.,BCl3).NH3+BCl3=H3NàBCl3
Forms addition compounds with Lewis acids(e.g.,BCl3)PH3+BCl3=H3PàBCl3.
Differences(i) Odour Characteristics ammonical
smell.Unpleasant smell of rotten fish.
(ii) Poisonous nature
Nonpoisonous. Poisonous.
(iii) Solubility Highly soluble in water. Sparingly soluble in water.(iv) Basic nature Basic in nature; its aqueous
solution turns red litmus blue.Very weakly basic; no action with litmus.
(v) Reaction with CuSO4
Gives blue solution of the complex compound[Cu(NH3)4]SO4.CuSO4+4NH3à[Cu(NH3)4]SO4
Gives a black precipitate of silver phosphide.3CuSO4+2PH3àCu3P2+3H2SO4
(vi) Hydrogen Bond
Hydrogen bonds are present in ammonia because of which it is an associated molecule in the liquid state.
Hydrogen bonds are not present in phosphine.
(vii) Reducing character
No reducing property. Phosphine is a reducing agent.It reduces AgNO3 into Ag.
Comparison of properties of White and Red phosphorous
Property White phosphorous Red Phosphorous
(i) State Translucent Brittle substance(ii) Colour White, gets yellowish on exposure to light Red(iii) Odour Garlic like odour Odourless
(iv) Hardness Wax like soft and can be cut by knife Hard(v) Poisonous nature Poisonous Non-poisonous(vi) Solubility Soluble in CS2 Insoluble in CS2
(vii) Ignition temperature About 303 K; burns spontaneously 543 K, burns only when heated
(viii) Stability Unstable, gradually changes into red phosphorous Stable(ix) Phosphorescence Shows Phosphorescence No Phosphorescence(x) Action of air Burns in air producing forms of P4O10 Does not burn in air(xi) Reactivity Very reactive Less reactive(xii) Action of chlorine Burns readily in Cl2 forming PCl3 and PCl5. Combines with Cl2
only on heating.(xiii) Action of hot NaOH Phosphine is evolved No action(xiv) Action of CuSO4 Copper is precipitated No action.
Difference Between Rhombic And Monoclinic Sulphur
Rhombic Sulphur Monoclinic sulphur1. It is common form of sulphur
andIs stable below 368.6 K
1. It is stable between 368.6 K to 393 K
2. It is amber coloured crystalline solid.
2. It is dull yellow needle shaped solid.
3. It melts at 385.8 K. 3. It melts at 392.9K.
4. It is insoluble in water but soluble in CS2
4. It is soluble in CS2.
5. Its density is 2.07 gm./cm3 5. Its density is 1.95gm./cm3
Comparision Of PCl3 & PCl5
PCl3
PCl5
PREPARATION P4 + 6Cl2 à 4PCl3
P4 + 8SOCl2 à 4PCl3 + 4SO2 + 2S2Cl2
PREPARATION P4 + 10Cl2 à 4PCl5
P4 + 10SO2Cl2 à 4PCl5 + 10SO2
PROPERTIES It is colourless oily liquid and hydrolysis in
presence of moisture PCl3 + 3H2O à H3PO3 + 3HCl It react with Organic compounds containing
OH group. 3CH3COOH + PCl3 à 3H3COCl + H3PO3
3C2H5OH + PCl3 à 3C2H5Cl + H3PO3
It has a pyramidal shape in which
PROPERTIES PCl5 is a yellowish white powder and
in moist air, it hydrolysis to POCl3 and finally gets converted to phosphoric acid. PCl5 + H2O à POCl3 + 2HCl POCl3 + 3H2O à H3PO4 + 3HCl
It reacts with organic compounds containing -OH group converting them to Chloro derivatives
CH3COOH + PCl5 à CH3COCl + POCl3 +HCl C2H5OH + PCl5 à C2H5Cl + POCl3 +HCl
phosphorus is sp3 hybridised It has a Trigonal-bi-pyramidal shape in which phousphorus is in sp3d