JEE Chemistry Physical and Inorganic Chemistry Notes Set 01

Physical Chemistry Essentials

1. Gas volumes in combustion give mole ratios directly (Gay-Lussac). For \(\ce{C_xH_y}\): \(x\) volumes \(\ce{CO2}\) and \(y/2\) volumes \(\ce{H2O}\).
2. pH + pOH = 14. Precipitation starts when the ionic product equals \(K_{sp}\).
3. Thermochemistry: \(\Delta_fH = \sum \Delta_cH(\text{reactants}) - \sum \Delta_cH(\text{products})\). For isochoric processes \(\Delta U = q_V\).
4. Graham's law: time of effusion \(\propto \sqrt M\).
5. Octahedral void radius \(r = 0.414R\), tetrahedral \(0.225R\).
6. Kinetics: the slow step fixes the rate law. A graph of \(\log k\) against \(1/T\) has slope \(-E_a/2.303R\).
7. Henry's law: gas solubility rises with pressure and falls with temperature.
8. Colligative properties: \(\Delta T_b = K_bm\), \(\Delta T_f = K_fm\). Halving the molality halves the shift.
9. Gold number: mg of protective colloid that stops coagulation of 10 mL of gold sol by 1 mL of 10 percent NaCl.
10. A species with higher reduction potential oxidises the reduced form of one with lower potential.

Inorganic Chemistry Essentials

1. Disproportionation: one element is both oxidised and reduced.
2. VSEPR: \(\ce{XeO3}\) pyramidal, \(\ce{ClF3}\) T-shaped, \(\ce{XeOF4}\) square pyramidal, \(\ce{XeF2}\) linear.
3. Dipole moment of a bent triatomic molecule \(= 2\mu_0\cos(\theta/2)\).
4. Group 1 carbonates (except Li) do not decompose on heating. Mg3N2 gives 2 mol NH3 per mole with water.
5. Boron has maximum covalency 4. Diborane has two 3c-2e bridge bonds.
6. Pb(IV) oxidises iodide, so PbI4 does not exist (inert pair effect).
7. Hardness of water comes from soluble bicarbonates, chlorides and sulphates of Ca and Mg.
8. Roasting of cinnabar gives mercury directly. Geometrical isomerism in octahedral complexes needs at least two ligands of each kind.