Most Important Inorganic Trends

Ionic Size: $Mg^{2+} < Na^{+} < F^{-} < O^{2-}$

Acidity of Oxides: $Na_{2}O_{2} < MgO < ZnO < P_{2}O_{5}$

First Ionisation Energy: $Na < Al < Mg < Si$

Bond Length: $N_{2} (Triple) < O_{2} (Double) < F_{2} (Single) < Cl_{2}$

Ionic Size: $Ca^{2+} < K^{+} < Ar < Cl^{-} < S^{2-}$

Acid Strength: $HClO < HClO_{2} < HClO_{3} < HClO_{4}$

Bond Strength: $HI < HBr < HCl < HF$

Oxidation state: $HI (-1) < I_{2} (0) < ICl (+1) < HIO_{4} (+7)$

Thermal Stability: $HClO < HClO_{2} < HClO_{3} < HClO_{4}$

Bond Enthalpy: $F_{2} < Cl_{2} < O_{2} < N_{2}$

Acidic Character: $K_2O < MgO < CO_{2} < SO_{3}$

Ionic Size: $Mg^{2+} < Na^{+} < F^{-} < O^{2-} < N^{3-}$

Basic Character: $NiO < MgO < SrO < K_{2}O < Cs_{2}O$

Extent of Hydrolysis: $CCl_{4} < MgCl_{2} < AlCl_{3} < SiCl_{4} < PCl_{5}$

H Bonding Strength: $S < N < Cl < O < F$

Hydrated ionic Radius: $Cs^{+} < Rb^{+} < K^{+} < Na^{+} < Li^{+}$

Molar Conductivity in water: $Li^{+} < Na^{+} < K^{+} < Rb^{+} < Cs^{+}$

Reactivity with water: $Li < Na < K < Rb < Cs$

Reactivity with Hydrogen: $Li > Na > K > Rb > Cs$

Melting Point (Alkali Metals): $Li > Na > K > Rb > Cs$

Basic Nature (Alkali Hydroxides): $LiOH < NaOH < KOH < RbOH < CsOH$

Thermal Stability: $LiOH < NaOH < KOH < RbOH < CsOH$

Covalent Character: $LiCl < LiBr < LiI$

Ionic Character: $BeCl_{2} < MgCl_{2} < CaCl_{2} < SrCl_{2} < BaCl_{2}$

Solubility: $MgCO_{3} > CaCO_{3} > SrCO_{3} > BaCO_{3}$

Solubility: $MgF_{2} < CaF_{2} < SrF_{2} < BaF_{2}$ (Note: $BeF_2$ is highly soluble)

Solubility: $Mg(OH)_{2} < Ca(OH)_{2} < Sr(OH)_{2} < Ba(OH)_{2}$

Basicity: $Be(OH)_{2} < Mg(OH)_{2} < Ca(OH)_{2} < Ba(OH)_{2}$

Hydration Enthalpy (Group 2): $Be^{2+} > Mg^{2+} > Ca^{2+} > Sr^{2+} > Ba^{2+}$

Reactivity with water: $Be < Mg < Ca < Sr < Ba$

Reactivity. towards Air: $Be < Mg < Ca < Sr < Ba$

Solubility (Group 2 Sulphates): $BeSO_{4} > MgSO_{4} > CaSO_{4} > SrSO_{4} > BaSO_{4}$

Ionic Character: $BCl_{3} < AlCl_{3} < GaCl_{3}$

Lewis Acid Strength (Boron Halides): $BF_{3} < BCl_{3} < BBr_{3} < BI_{3}$

Lewis Acid Strength (Group 13): $AlCl_{3} > GaCl_{3} > InCl_{3}$

Reducing Power: $GeCl_{2} > SnCl_{2} > PbCl_{2}$

Oxidizing Power: $GeCl_{4} < SnCl_{4} < PbCl_{4}$

Catenation Tendency: $C > Si > Ge \approx Sn > Pb$

Basicity: $NH_{3} > PH_{3} > AsH_{3} > SbH_{3} > BiH_{3}$

Thermal Stability: $NH_{3} > PH_{3} > AsH_{3} > SbH_{3} > BiH_{3}$

Acidic Strength: $HNO_{3} > H_{3}PO_{4} > H_{3}AsO_{4} > H_{3}SbO_{4}$

Solubility in water: $HNO_{3} > H_{3}PO_{4} > H_{3}AsO_{4}$

Stability of +5 Oxidation State: $P > As > Sb > Bi$ (Due to Inert Pair Effect)

Extent of Hydrolysis: $NCl_3$ (Explosive), $PCl_3$ (Complete), $AsCl_3$ & $SbCl_3$ (Partial), $BiCl_3$ (Partial)

Stability of Hydrides: $H_{2}O > H_{2}S > H_{2}Se > H_{2}Te$

Poisonous Nature: $H_{2}O < H_{2}S < H_{2}Se < H_{2}Te$

Acidity: $H_{2}O < H_{2}S < H_{2}Se < H_{2}Te$

Acidic Strength: $H_{2}SO_{3} > H_{2}SeO_{3} > H_{2}TeO_{3}$

Stability: $H_{2}SO_{3} > H_{2}SeO_{3} > H_{2}TeO_{3}$

Acidic Strength: $H_{2}SO_{4} > H_{2}SeO_{4} > H_{6}TeO_{6}$

Oxidizing Power: $H_{2}SO_{4} < H_{2}SeO_{4} < H_{6}TeO_{6}$

Electron Affinity (Halogens): $I < Br < F < Cl$ (Note: F < Cl due to repulsion)

Reducing Power : $HF < HCl < HBr < HI$

Affinity for Hydrogen: $F_{2} > Cl_{2} > Br_{2} > I_{2}$

Acidity: $HF < HCl < HBr < HI$

MP: $HCl < HBr < HI < HF$ (HF highest due to H-bonding)

BP: $HCl < HBr < HI < HF$

Acidity: $HIO_{3} < HBrO_{3} < HClO_{3}$

Covalent Character: $TiCl_{2} < TiCl_{3} < TiCl_{4}$

Magnetic Moment: $Zn^{2+} (0) < Cu^{2+} < Ni^{2+} < Co^{2+} < Fe^{2+} < Mn^{2+}$

Ionic Character: $VCl_{2} > VCl_{3} > VCl_{4}$

Electropositivity: $Hg < Cu < Na < Li < Cs$

Density: $Al < Fe < Pb < Au$

Basicity: $Li_{2}O > BeO > B_{2}O_{3} > CO_{2}$

Electronegativity: $As < P \approx H < S < C < Cl$

Ionisation Energy: $O < N < F$ (N > O due to half-filled p-orbital)

Atomic Size: $O < C < S < Se$

Acidity: $HOCl > HOBr > HOI$

Density: $H_{2} < NH_{3} < O_{2} < H_{2}S < CO_{2}$

Thermal Stability: $HF > HCl > HBr > HI$

Bond Enthalpy: $I_{2} < F_{2} < Br_{2} < Cl_{2}$ (F2 is low due to repulsion)

Melting Point: $CaI_{2} < CaBr_{2} < CaCl_{2} < CaF_{2}$

Oxidizing Power: $O > S > Se > Te$

Oxidizing Power: $F_{2} > Cl_{2} > Br_{2} > I_{2}$

Atomic Size: $B < Be < Li < Na$

Bond Length: $N-N < O-O < F-F$ (Usually H-H shortest, but among these: O-O < N-N < F-F is wrong. N-N 1.45, O-O 1.48, F-F 1.42. F-F is usually sho...

Stability of Hydrides: $LiH > NaH > KH > RbH > CsH$

pH of Aqueous Solution: $NaCl (7) > MgCl_{2} > AlCl_{3}$

Acidity: $MgO < Al_{2}O_{3} < SiO_{2} < P_{4}O_{10}$

Nucleophilicity (in Polar Protic Solvent): $F^{-} < Cl^{-} < Br^{-} < I^{-}$

Basicity: $F^{-} < OH^{-} < NH_{2}^{-} < CH_{3}^{-}$

Boiling Point: $PH_{3} < AsH_{3} < NH_{3} < SbH_{3} < BiH_{3}$ (Note: $NH_3$ is high due to H-bond)

Ionization Energy: $B < C < O < N < F < Ne$

Thermal Stability: $BeCO_{3} < MgCO_{3} < CaCO_{3} < SrCO_{3} < BaCO_{3}$

Paramagnetism (Elements): $O$ (Paramagnetic), $N$ (Paramagnetic), $Ca, Al$ (Paramagnetic as metals? Al is para, Ca is para).

Ionic Character: $LiBr < NaBr < KBr < RbBr < CsBr$

Hydration Energy: $Be^{2+} > Mg^{2+} > Ca^{2+} > Sr^{2+} > Ba^{2+}$

Bond Angle: $NH_{3} (107^{\circ}) > PH_{3} (93^{\circ}) > AsH_{3} > SbH_{3}$

Bond Angle: $AsF_{3} < PF_{3} < NF_{3}$ (Trend is usually $PF_3 < PCl_3$ )

Bond Angle: $H_{2}O (104.5^{\circ}) > H_{2}S (92^{\circ}) > H_{2}Se > H_{2}Te$

Bond Angle: $NF_{3} < NCl_{3}$

Bond Angle: $NO_{2}^{-} < NO_{2} < NO_{2}^{+}$

Bond Angle: $NF_{3} < NH_{3}$

Bond Angle: $PH_{3} < PF_{3}$

Size: $O < O^{-} < O^{2-}$

Dipole Moment: $CH_{3}Cl > CH_{2}Cl_{2} > CHCl_{3} > CCl_{4}$

Ionic Nature: $MCl > MCl_{2} > MCl_{3}$

Strength of H-Bonding: $S < Cl < N < O < F$

NO Bond Length: $NO_{2}^{+} < NO_{2} < NO_{2}^{-} < NO_{3}^{-}$

Bond Order: $O_{2}^{2-} (1) < O_{2}^{-} (1.5) < O_{2} (2) < O_{2}^{+} (2.5)$