heating effects (12th&13th)

7/25/2019 Heating Effects (12th&13th)

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HEATING EFFECTS

XII(ABCD) & XIII(XYZ)

BANSALCLASSES TARGET IIT JEE 2007

INORGANICCHEMISTRY


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Bansal Classes Heating Effects [2]

HEATING EFFECTS

Heating effect of carbonate & bicarbonate salts

All carbonates except (Na, K, Rb, Cs) decompose on heating giving CO2

Li2CO

3Li

2O + CO

2

MCO3MO + CO

2[M = Be, Mg, Ca, Sr, Ba]

Yellow 32

COAg Black

Ag2 + CO2+

2

1O

2

carbonate)II(CuBasic

32CuCO.)OH(Cu

2CuO + CO2+ H

2O

white3

ZnCO

)cold(white)hot(Yellow

ZnO + CO2

PbCO3

YellowPbO + CO

2

White

OHCOCOOPb)OH(Pb.PbCO22243

C450

23

HgCO3Hg + 2

1

O2+ CO2

(NH4)2CO

32NH

3+ H

2O + CO

2

All bicarbonates decompose to give carbonates and CO2. eg.

2NaHCO3

Na

2CO

3+ CO

2+ H

2O

[General reaction 3

HCO2 23

CO +H2O + CO

2]

Heating effect of ammonium salts

(NH4)2Cr

2O

7N

2+ Cr

2O

3+ 4H

2O

NH4NO

2N

2+ 2H

2O

NH4NO3N2O + 2H2O2NH4

ClO4N

2+ Cl

2+ 2O

2+ 4H

2O

2NH4IO

3N

2+ I

2+ O

2+ 4H

2O

[If anionic part is oxdising in nature, then N2will be the product (some times N

2O).]

(NH4)2HPO

4HPO

3+ H

2O + 2NH

3

(NH4)2SO

4NH

3+ H

2SO

4

2(NH3)3PO

42NH

3+ P

2O

5+ 3H

2O

(NH4)2CO

32NH

3+ H

2O + CO

2

[If anionic part weakly oxidising or non oxidising in nature then NH3will be the product.]

Heating effect of nitrate salts

MNO3KNO2+ 2

1 O2

[M = Na, K, Rb, Cs]

2LiNO3Li

2O + 2NO

2+

2

1O

2

2M(NO3)22MO + 4NO

2+ O

2

[M = all bivalent metals eg. Zn+2, Mg+2, Sr+2, Ca+2, Ba+2, Cu+2, Pb+2]

Hg(NO3)2Hg + 2NO

2+ O

2; 2AgNO

32Ag + 2NO

2+ O

2

Heating effect of Halides salts

2FeCl3 2FeCl

2+ Cl

2; AuCl

3AuCl + Cl

2

Hg2Cl2HgCl2+ Hg ; NH4ClNH3+ HClPb(SCN)4 Pb(SCN)

2+ (SCN)

2


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PbCl4 PbCl

2+ Cl

2[PbBr

2 PbBr

2+ Br

2& PbI

4does not exists]

Heating effect of hydrated chloride salts

MgCl2. 6H

2O

MgO + 2HCl + 5H2O

2FeCl3. 6H

2OFe

2O

3+ 6HCl + 9H

2O

2AlCl3. 6H

2OAl

2O

3+ 6HCl + 9H

2O

Pink OH2

C50

222OH6.CoCl

Pink OH2C58

222

OH4.CoCl

violetdRe OH2C140

222

OH2.CoCl

Blue 2CoCl

Heating effect of hydrated Sulphate salts

vitriolBlue

OH5.CuSO24

OH4

C100

2

WhiteBluish

OH.CuSO24

OH

C220

2

White

4CuSO

C800CuO + SO

2+

2

1O

2

BlackCuO + SO3

VitriolGreen

OH7.FeSO24 OH7

C300

2

FeSO4

Fe2SO

3+ SO

2+ SO

3(very important)

Fe2(SO

4)3

Fe2O

3+ 3SO

3

saltepsom OH7.MgSO 24 OH7 2

MgSO4 [Same as ZnSO4]

gypsum

OH2.CaSO24

C120 (CaSO4.2

1H

2O) +1

2

1H

2O

Plaster of pairs

OH2.CaSO24

burntDead

4CaSO +

2

1H

2O

Na2S

2O

3.5H

2O

C220Na

2S

2O

3 + 5H

2O

3Na2SO4+ Na2S5.ZnSO

4.7H

2O

C70 ZnSO4.6H

2O

C20070 ZnSO4.H

2O

C200 ZnSO4

ZnO + SO2+

2

1O

2

2NaHSO3

2NaHSO4

Na2SO

4+ H

2O + SO

3

Heating effect of Oxide salts

2Ag2O

C300

4Ag + O2

;yellowHgO

C400

red

HgOheatingstrong Hg +

21 O

2

PbO2

PbO +

2

1O

2;

leadRed43

OPb Litharge

PbO6 + O2

3MnO2

C900 Mn3O

4+ O

2;

white

ZnO

yellow

ZnO

2CrO5Cr

2O

3+

2

1O

2;

yellow

PbO

Red

PbO

(Massicot) (Litharge)2CrO

3

C420 Cr2O

3+

2

3O

2; I

2O

5I

2+

2

5O

2


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Heating effect of dichromate & chromate salts

(NH4)2Cr

2O

7

N2+ Cr

2O

3+ 4H

2O

K2Cr

2O

7

2K2CrO

4+ Cr

2O

3+

2

7O

2

Heating effect of phosphate salts

NaH2PO

4

H

2O + NaPO

3

1 phosphate salt

Na2HPO

4

H2O + Na

2P

2O

72 phosphate salt

Na3PO

4 No effect

3 phosphate salt

Na(NH4)HPO

4.4H

2O

OH4 2

NaNH4HPO

4

.tempHigh NaPO

3+ NH

3+ H

2O

2Mg(NH4)PO

4

Mg2P

2O

7+ 2NH

3+ H

2O

Heating effect of Acids

2HNO3

H2O + 2NO2+ 2

1

O2

H2SO

4

C444H

2O + SO

3

H2SO

4 C800 H2O + SO2+ 2

1O

2

3H2SO

3 2H

2SO

4+ S+ H

2O

3HNO2 HNO

3+ 2NO + H

2O

HClO3 HClO

4+ ClO

2+ H

2O

3HOCl 2HCl +HClO3

4H3PO

3

C200

3H3PO

4+ PH

3

2H3PO

2H

3PO

4+ PH

3

2NaH2PO

2Na

2HPO

4+ PH

3

H3PO

4

C220 H4P

2O

7

C320 4HPO3

C320 2P2O

5+ 2H

2O

H3BO

3

C100 4HBO2

C140 H2B

4O

7

hot

dRe 2B2O

3+ H

2O

H2C

2O

4 H

2O + CO + CO

2

Heating effects of acetate, formate, oxalate salts

CH3CO2K

K2CO3 + CH3COCH3 Na2C2O4Na2CO3+ COPb(OAc)

2

PbO + CO2+ CH

3COCH

3SnC

2O

4

SnO + CO2+ CO

Mg(OAc)2MgO + CO

2+ CH

3COCH

3FeC

2O

4FeO + CO + CO

2

Be(OAc)2BeO + CO2+ CH3COCH3 Ag2C2O4

2Ag + 2CO2

Ca(OAc)2CaCO

3+ CH

3COCH

3HgC

2O

4Hg + 2CO

2

Ba(OAc)2BaCO

3+ CH

3COCH

3

HCO2Na

C350 Na2C

2O

4+ H

2

2HCOOAg HCOOH + 2Ag + CO

2

(HCOO)2HgHCOOH + Hg + CO

2

heating effects (12th&13th)

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