Ultimate JEE Inorganic Chemistry Cheat Sheet
Master the most frequently tested inorganic reactions for JEE Main and Advanced. Use the search bar below to instantly find specific reactions, catalysts, or compounds.
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s-Block Elements
1. Peroxide Formation
$$\ce{2Na + O2(excess) ->[\Delta] Na2O2}$$
Sodium reacts with excess oxygen to form sodium peroxide.
2. Superoxide Formation
$$\ce{K + O2(excess) ->[\Delta] KO2}$$
Potassium forms superoxides directly with excess oxygen. Rb and Cs do the same.
3. Normal Oxide
$$\ce{4Li + O2 ->[\Delta] 2Li2O}$$
Lithium primarily forms the normal oxide due to its small size.
4. Castner-Kellner Cell
$$\ce{2NaCl + 2H2O -> 2NaOH + Cl2 ^ + H2 ^}$$
Electrolysis of brine solution using a mercury cathode to prepare Sodium Hydroxide.
5. Solvay Process (Recovery)
$$\ce{2NH4Cl + Ca(OH)2 -> 2NH3 ^ + CaCl2 + 2H2O}$$
Recovery of ammonia. This makes CaCl2 the only major byproduct of the process.
6. Heating Bicarbonates
$$\ce{Ca(HCO3)2 ->[\Delta] CaCO3 v + H2O + CO2 ^}$$
Removal of temporary hardness by boiling; soluble bicarbonates decompose to insoluble carbonates.
7. Beryllium Hydride Prep
$$\ce{2BeCl2 + LiAlH4 -> 2BeH2 + LiCl + AlCl3}$$
BeH2 cannot be made by direct elemental combination. Requires reduction with LAH.
8. Heating Li2CO3
$$\ce{Li2CO3 ->[\Delta] Li2O + CO2 ^}$$
Unlike other alkali carbonates, lithium carbonate is thermally unstable and decomposes readily.
9. Heating Mg(NO3)2
$$\ce{2Mg(NO3)2 ->[\Delta] 2MgO + 4NO2 ^ + O2 ^}$$
Alkaline earth metal nitrates decompose to give the metal oxide, nitrogen dioxide, and oxygen.
10. Heating NaNO3
$$\ce{2NaNO3 ->[\Delta] 2NaNO2 + O2 ^}$$
Alkali metal nitrates (except Li) decompose to yield nitrites and oxygen gas.
11. Bleaching Powder Prep
$$\ce{Ca(OH)2 + Cl2 -> CaOCl2 + H2O}$$
Reaction of dry slaked lime with chlorine gas.
12. Plaster of Paris
$$\ce{CaSO4.2H2O ->[\Delta 393 K] CaSO4.1/2H2O + 3/2 H2O}$$
Controlled heating of gypsum yields calcium sulphate hemihydrate (Plaster of Paris).
13. Amphoteric BeO
$$\ce{BeO + 2NaOH -> Na2BeO2 + H2O}$$
Beryllium oxide shows amphoterism by dissolving in alkali to form sodium beryllate.
14. Magnesium Nitride
$$\ce{3Mg + N2 ->[\Delta] Mg3N2}$$
Direct combination with nitrogen from air upon burning.
15. Lithium Nitride
$$\ce{6Li + N2 ->[\Delta] 2Li3N}$$
Lithium is the only alkali metal that directly reacts with atmospheric nitrogen.
p-Block: Boron & Carbon Families
16. Diborane Prep
$$\ce{4BF3 + 3LiAlH4 -> 2B2H6 + 3LiF + 3AlF3}$$
Laboratory preparation of diborane using lithium aluminum hydride in diethyl ether.
17. Borazine (Inorganic Benzene)
$$\ce{3B2H6 + 6NH3 ->[\Delta] 2B3N3H6 + 12H2}$$
Reaction of diborane with ammonia at high temperatures yields borazine.
18. Diborane Hydrolysis
$$\ce{B2H6 + 6H2O -> 2H3BO3 + 6H2 ^}$$
Highly exothermic hydrolysis yielding orthoboric acid and hydrogen.
19. Heating Borax
$$\ce{Na2B4O7.10H2O ->[\Delta] Na2B4O7 ->[\Delta] 2NaBO2 + B2O3}$$
Forms Borax glass (Sodium metaborate + Boric anhydride) for the Borax Bead Test.
20. Silicone Formation
$$\ce{n(CH3)2SiCl2 + nH2O -> [-O-Si(CH3)2-]_n + 2nHCl}$$
Hydrolysis followed by condensation of dialkyldichlorosilanes.
21. Diborane with CO
$$\ce{B2H6 + 2CO -> 2BH3.CO}$$
Symmetrical cleavage of diborane by a soft Lewis base like carbon monoxide.
22. Diborane Cleavage
$$\ce{B2H6 + 2NMe3 -> 2BH3.NMe3}$$
Cleavage by trimethylamine to form an adduct.
23. Boric Acid as Lewis Acid
$$\ce{H3BO3 + H2O <=> [B(OH)4]- + H+}$$
Boric acid does not donate a proton directly; it accepts OH- from water.
24. Al Amphoterism
$$\ce{2Al + 2NaOH + 6H2O -> 2Na[Al(OH)4] + 3H2 ^}$$
Aluminum dissolves in strong alkali to form sodium tetrahydroxoaluminate.
25. Thermite Process
$$\ce{Fe2O3 + 2Al ->[\Delta] 2Fe + Al2O3}$$
Highly exothermic redox reaction used in welding iron tracks.
26. Silica with HF
$$\ce{SiO2 + 4HF -> SiF4 + 2H2O}$$
Glass etching reaction. HF is the only common acid that attacks silica.
27. Fluorosilicic Acid
$$\ce{SiF4 + 2HF -> H2SiF6}$$
Silicon tetrafluoride dissolves in excess HF to form this strong acid.
28. Water Gas Prep
$$\ce{C + H2O(g) ->[473-1273 K] CO ^ + H2 ^}$$
Passing steam over red-hot coke produces synthesis gas (syngas/water gas).
29. Producer Gas Prep
$$\ce{2C + O2 + 4N2 ->[1273 K] 2CO ^ + 4N2 ^}$$
Passing air over red-hot coke.
30. Red Lead with HNO3
$$\ce{Pb3O4 + 4HNO3 -> PbO2 + 2Pb(NO3)2 + 2H2O}$$
Proof that Pb3O4 is a mixed oxide (2PbO·PbO2). PbO dissolves, PbO2 remains insoluble.
p-Block: Nitrogen Family
31. Haber Process
$$\ce{N2 + 3H2 <=>[Fe, Mo] 2NH3}$$
Industrial synthesis of ammonia. High pressure and low temp favor forward reaction.
32. Ostwald Process
$$\ce{4NH3 + 5O2 ->[Pt/Rh, 500 K] 4NO + 6H2O}$$
Catalytic oxidation of ammonia, step 1 in manufacturing Nitric Acid.
33. P4 Disproportionation
$$\ce{P4 + 3NaOH + 3H2O -> PH3 ^ + 3NaH2PO2}$$
White phosphorus with boiling conc. NaOH gives phosphine and sodium hypophosphite.
34. Cu with Dilute HNO3
$$\ce{3Cu + 8HNO3(dil) -> 3Cu(NO3)2 + 2NO ^ + 4H2O}$$
Less reactive metals give Nitric Oxide (NO) with dilute acid.
35. Zn with Dilute HNO3
$$\ce{4Zn + 10HNO3(dil) -> 4Zn(NO3)2 + N2O ^ + 5H2O}$$
More reactive metals give Nitrous Oxide (N2O) with dilute acid.
36. Cu with Conc HNO3
$$\ce{Cu + 4HNO3(conc) -> Cu(NO3)2 + 2NO2 ^ + 2H2O}$$
Almost all metals give brown Nitrogen Dioxide (NO2) with conc. nitric acid.
37. Zn with Conc HNO3
$$\ce{Zn + 4HNO3(conc) -> Zn(NO3)2 + 2NO2 ^ + 2H2O}$$
Zinc also yields brown NO2 gas with concentrated HNO3.
38. I2 with Conc HNO3
$$\ce{I2 + 10HNO3(conc) -> 2HIO3 + 10NO2 ^ + 4H2O}$$
Non-metals are oxidized to their highest oxyacids (Iodine to Iodic acid).
39. C with Conc HNO3
$$\ce{C + 4HNO3(conc) -> CO2 ^ + 4NO2 ^ + 2H2O}$$
Carbon is oxidized to Carbon Dioxide.
40. P4 with Conc HNO3
$$\ce{P4 + 20HNO3(conc) -> 4H3PO4 + 20NO2 ^ + 4H2O}$$
Phosphorus is oxidized to Phosphoric Acid.
41. S8 with Conc HNO3
$$\ce{S8 + 48HNO3(conc) -> 8H2SO4 + 48NO2 ^ + 16H2O}$$
Sulfur is oxidized to Sulfuric Acid.
42. Heating NH4NO3
$$\ce{NH4NO3 ->[\Delta] N2O ^ + 2H2O}$$
Ammonium nitrate decomposes to laughing gas (Nitrous oxide).
43. Heating NH4NO2
$$\ce{NH4NO2 ->[\Delta] N2 ^ + 2H2O}$$
Ammonium nitrite decomposes to yield pure Nitrogen gas.
44. Volcano Reaction
$$\ce{(NH4)2Cr2O7 ->[\Delta] N2 ^ + Cr2O3 + 4H2O}$$
Thermal decomposition of ammonium dichromate yields N2 and green Cr2O3 ash.
45. PCl5 Hydrolysis
$$\ce{PCl5 + 4H2O -> H3PO4 + 5HCl}$$
Complete hydrolysis yields phosphoric acid. (Partial gives POCl3).
p-Block: O, Halogens & Noble Gases
46. Contact Process
$$\ce{2SO2 + O2 <=>[\ce{V2O5}] 2SO3}$$
Key reversible step in manufacturing sulfuric acid, favored by high pressure.
47. Cl2 + Cold Dil NaOH
$$\ce{Cl2 + 2NaOH(cold, dil) -> NaCl + NaOCl + H2O}$$
Disproportionation to chloride and hypochlorite.
48. Cl2 + Hot Conc NaOH
$$\ce{3Cl2 + 6NaOH(hot, conc) -> 5NaCl + NaClO3 + 3H2O}$$
Disproportionation proceeds further to yield sodium chlorate.
49. XeF6 Complete Hydrolysis
$$\ce{XeF6 + 3H2O -> XeO3 + 6HF}$$
Yields highly explosive Xenon trioxide.
50. XeF6 Partial (1 H2O)
$$\ce{XeF6 + H2O -> XeOF4 + 2HF}$$
Partial hydrolysis forming xenon oxytetrafluoride.
51. XeF6 Partial (2 H2O)
$$\ce{XeF6 + 2H2O -> XeO2F2 + 4HF}$$
Partial hydrolysis forming xenon dioxydifluoride.
52. Cu with Conc H2SO4
$$\ce{Cu + 2H2SO4(conc) -> CuSO4 + SO2 ^ + 2H2O}$$
Conc. H2SO4 acts as a moderate oxidizing agent, yielding SO2 gas.
53. Sugar Charring
$$\ce{C12H22O11 ->[\ce{H2SO4(conc)}] 12C + 11H2O}$$
Demonstrates the intense dehydrating property of concentrated sulfuric acid.
54. Ozone Decomposition
$$\ce{2O3 -> 3O2}$$
Thermodynamically highly favorable process ($\Delta H < 0, \Delta S > 0$).
55. Tailing of Mercury
$$\ce{2Hg + O3 -> Hg2O + O2 ^}$$
Ozone destroys the meniscus of mercury, making it stick to glass.
56. Ozone Test
$$\ce{2I- + H2O + O3 -> 2OH- + I2 + O2 ^}$$
Quantitative estimation of ozone using KI and titrating the liberated iodine.
57. F2 with Water
$$\ce{2F2 + 2H2O -> 4HF + O2 ^}$$
Fluorine is so reactive it oxidizes water to oxygen.
58. Cl2 with Water
$$\ce{Cl2 + H2O -> HCl + HOCl}$$
Chlorine water acts as a bleaching agent due to the nascent oxygen from HOCl.
59. Lab Prep of Cl2
$$\ce{MnO2 + 4HCl ->[\Delta] MnCl2 + Cl2 ^ + 2H2O}$$
Oxidation of HCl by Manganese dioxide.
60. Deacon's Process
$$\ce{4HCl + O2 ->[\ce{CuCl2}] 2Cl2 + 2H2O}$$
Industrial production of chlorine gas.
61. KMnO4 with HCl
$$\ce{2KMnO4 + 16HCl -> 2KCl + 2MnCl2 + 5Cl2 ^ + 8H2O}$$
Potassium permanganate rapidly oxidizes HCl to chlorine gas.
62. F2 + Cold Dil NaOH
$$\ce{2F2 + 2NaOH(dil) -> 2NaF + OF2 ^ + H2O}$$
Unlike chlorine, fluorine gives Oxygen difluoride with cold dilute base.
63. F2 + Hot Conc NaOH
$$\ce{2F2 + 4NaOH(conc) -> 4NaF + O2 ^ + 2H2O}$$
With hot concentrated base, fluorine gas liberates oxygen.
64. ICl Formation
$$\ce{I2 + Cl2(eq) -> 2ICl}$$
Equimolar interhalogen formation.
65. ICl3 Formation
$$\ce{I2 + 3Cl2(excess) -> 2ICl3}$$
Reaction with excess chlorine gives the higher interhalogen.
66. H2S with Cl2
$$\ce{H2S + Cl2 -> 2HCl + S v}$$
Chlorine oxidizes hydrogen sulfide to elemental sulfur.
67. SO2 with Cl2
$$\ce{SO2 + Cl2 -> SO2Cl2}$$
Formation of sulfuryl chloride.
68. XeF2 Formation
$$\ce{Xe(excess) + F2 ->[673 K, 1 bar] XeF2}$$
Requires an excess of Xenon to stop at the difluoride stage.
69. XeF4 Formation
$$\ce{Xe + 2F2 ->[873 K, 7 bar] XeF4}$$
Prepared using a 1:5 ratio of Xe to F2.
70. XeF6 Formation
$$\ce{Xe + 3F2 ->[573 K, 60-70 bar] XeF6}$$
Prepared using a 1:20 ratio of Xe to F2 under extreme pressure.
d-Block Elements
71. Heating KMnO4
$$\ce{2KMnO4 ->[\Delta] K2MnO4 + MnO2 + O2 ^}$$
Decomposes to potassium manganate, manganese dioxide, and oxygen.
72. Chromate-Dichromate Eq
$$\ce{2CrO4^2- + 2H+ <=> Cr2O7^2- + H2O}$$
Yellow chromate converts to orange dichromate in acidic medium (pH dependent).
73. Permanganate (Acidic)
$$\ce{MnO4^- + 8H+ + 5e- -> Mn^2+ + 4H2O}$$
Standard reduction of permanganate ion in acidic titrations (n-factor = 5).
74. Permanganate (Basic/Neutral)
$$\ce{MnO4^- + 2H2O + 3e- -> MnO2 v + 4OH-}$$
Reduction yielding brown precipitate of MnO2 (n-factor = 3).
75. Dichromate Reduction
$$\ce{Cr2O7^2- + 14H+ + 6e- -> 2Cr^3+ + 7H2O}$$
Orange dichromate reduces to green Cr(III) ions (n-factor = 6).
76. Pyrolusite to Manganate
$$\ce{2MnO2 + 4KOH + O2 ->[\Delta] 2K2MnO4 + 2H2O}$$
Step 1 of KMnO4 prep: oxidative fusion of pyrolusite ore.
77. Manganate Disproportionation
$$\ce{3MnO4^2- + 4H+ -> 2MnO4^- + MnO2 + 2H2O}$$
Step 2: Green manganate disproportionates in acidic/neutral medium to purple permanganate.
78. Chromite to Chromate
$$\ce{4FeCr2O4 + 8Na2CO3 + 7O2 ->[\Delta] 8Na2CrO4 + 2Fe2O3 + 8CO2}$$
Step 1 of K2Cr2O7 prep: Roasting chromite ore with soda ash.
79. Chromate to Dichromate
$$\ce{2Na2CrO4 + H2SO4 -> Na2Cr2O7 + Na2SO4 + H2O}$$
Acidifying the yellow extract to get orange sodium dichromate.
80. Na vs K Dichromate
$$\ce{Na2Cr2O7 + 2KCl -> K2Cr2O7 + 2NaCl}$$
KCl is added because K2Cr2O7 is less soluble and crystallizes out easily.
81. KMnO4 + Fe(II)
$$\ce{5Fe^2+ + MnO4^- + 8H+ -> 5Fe^3+ + Mn^2+ + 4H2O}$$
Oxidation of ferrous salts to ferric salts in redox titrations.
82. KMnO4 + Oxalate
$$\ce{5C2O4^2- + 2MnO4^- + 16H+ -> 10CO2 ^ + 2Mn^2+ + 8H2O}$$
Oxidation of oxalate ions to carbon dioxide (needs ~60°C).
83. K2Cr2O7 + Iodide
$$\ce{6I- + Cr2O7^2- + 14H+ -> 3I2 + 2Cr^3+ + 7H2O}$$
Dichromate oxidizes iodide to iodine, which can be titrated with hypo.
84. Cu(II) with Iodide
$$\ce{2Cu^2+ + 4I- -> Cu2I2 v + I2}$$
Cu(II) is reduced to white Cu(I) iodide while oxidizing I- to I2.
85. Heating K2Cr2O7
$$\ce{4K2Cr2O7 ->[\Delta] 4K2CrO4 + 2Cr2O3 + 3O2 ^}$$
Decomposes on heating to give chromate, chromium(III) oxide, and oxygen.
Metallurgy
86. Roasting Zinc Blende
$$\ce{2ZnS + 3O2 ->[\Delta] 2ZnO + 2SO2 ^}$$
Heating sulfide ores in excess air to convert them to oxides.
87. Mond Process
$$\ce{Ni + 4CO ->[330-350 K] Ni(CO)4 ->[450-470 K] Ni + 4CO ^}$$
Refining Nickel via volatile nickel tetracarbonyl and thermal decomposition.
88. Van Arkel Process
$$\ce{Zr + 2I2 ->[870 K] ZrI4 ->[2075 K] Zr + 2I2 ^}$$
Ultra-purification of Zirconium (or Titanium) via volatile iodide.
89. MacArthur Forrest Cyanide
$$\ce{4Au + 8CN- + 2H2O + O2 -> 4[Au(CN)2]^- + 4OH-}$$
Leaching of gold ore using dilute cyanide solution in presence of air.
90. Zinc Displacement
$$\ce{2[Au(CN)2]^- + Zn -> [Zn(CN)4]^2- + 2Au v}$$
Recovery of pure gold by cementation/displacement using active Zinc powder.
Qualitative Salt Analysis & Coordination
91. Brown Ring Test
$$\ce{[Fe(H2O)6]^2+ + NO -> [Fe(H2O)5(NO)]^2+ + H2O}$$
Confirmatory for nitrate. Forms brown pentaaquanitrosoniumiron(I).
92. Chromyl Chloride Test
$$\ce{K2Cr2O7 + 4KCl + 6H2SO4 -> 2CrO2Cl2 ^ + 6KHSO4 + 3H2O}$$
Test for chloride. Emits deep red vapors of chromyl chloride.
93. Nessler's Reagent Test
$$\ce{2K2[HgI4] + NH3 + 3KOH -> H2N-Hg-O-Hg-I v + 7KI + 2H2O}$$
Test for ammonium ion. Forms brown Iodide of Millon's base.
94. Blood Red Complex
$$\ce{Fe^3+ + SCN- -> [Fe(SCN)]^2+}$$
Confirmatory test for Ferric ($Fe^{3+}$) ions with thiocyanate.
95. Prussian Blue
$$\ce{4Fe^3+ + 3[Fe(CN)6]^4- -> Fe4[Fe(CN)6]3 v}$$
Reaction of Ferric ions with potassium ferrocyanide.
96. Turnbull's Blue
$$\ce{3Fe^2+ + 2[Fe(CN)6]^3- -> Fe3[Fe(CN)6]2 v}$$
Reaction of Ferrous ions with potassium ferricyanide.
97. Copper(II) Ammine
$$\ce{Cu^2+ + 4NH3 -> [Cu(NH3)4]^2+}$$
Cu(II) forms a deep blue soluble complex with excess ammonia.
98. AgCl in Ammonia
$$\ce{AgCl + 2NH3 -> [Ag(NH3)2]+ + Cl-}$$
White precipitate of AgCl dissolves in ammonia to form diamminesilver(I).
99. Nickel DMG Test
$$\ce{Ni^2+ + 2DMG -> Ni(DMG)2 v + 2H+}$$
Nickel gives a bright rosy red precipitate with dimethylglyoxime in basic medium.
100. Nitroprusside Test
$$\ce{S^2- + [Fe(CN)5(NO)]^2- -> [Fe(CN)5(NOS)]^4-}$$
Sulfide ions give a brilliant purple/violet color with sodium nitroprusside.
101. Cobalt Thiocyanate
$$\ce{Co^2+ + 4SCN- -> [Co(SCN)4]^2-}$$
Cobalt forms a beautiful blue-colored complex with excess thiocyanate.
