Chemistry: Physical, Inorganic and Organic Essentials
BVP CET chemistry questions span atomic structure and periodicity, chemical bonding and hybridisation, thermodynamics, chemical and ionic equilibrium, redox and electrochemistry, kinetics, coordination compounds, p- and d-block trends, and organic chemistry from hydrocarbons through haloalkanes, alcohols, carbonyls, acids, amines, biomolecules and polymers. Physical chemistry supplies most of the numericals; organic supplies most of the elimination.
Quantitative core
The mole concept underlies all stoichiometry-balance the equation before touching numbers. For a weak acid, [H⁺] ≈ √(Ka·C) is valid only when dissociation is small (C/Ka > 100). Buffers follow pH = pKa + log([salt]/[acid]). ΔG° = −RT ln K links thermodynamics to equilibrium, and ΔG° = −nFE° links it to electrochemical cells.
Worked example
Find the pH of 0.10 M acetic acid, Ka = 1.8 × 10⁻⁵. Assume α is small: [H⁺] ≈ √(1.8×10⁻⁵ × 0.10) = √(1.8×10⁻⁶) = 1.34×10⁻³ M. Check: 1.34×10⁻³/0.10 = 1.3% dissociated, so the approximation is safe. pH = −log(1.34×10⁻³) = 3 − 0.13 = 2.87. The solution is acidic but nowhere near the pH 1.0 of 0.10 M HCl-partial ionisation is the whole point.
Traps
- Writing equilibrium expressions with pure solids or liquids included.
- Using Kp = Kc(RT)^Δn while ignoring Δn.
- Forgetting the ionisation-energy dips at group 13→14 and 15→16.
- Missing the lone pairs when assigning hybridisation (XeF₄ is sp³d², square planar).
- Swapping SN1 (tertiary, polar protic) with SN2 (primary, aprotic).
- Ignoring peroxide effect in HBr addition to unsymmetrical alkenes.