IIT-JEE MAINS 2027 cheat sheet for Physical Chemistry! 📱 Practice 1 Lakh+ PYQs on ExamBhai.com! - Free Study Material

Physical Chemistry Cheat Sheet: High-Yield Revision Guide

Mastering Physical Chemistry for IIT-JEE Mains 2027 requires a clear understanding of fundamental core principles and rapid problem-solving formulas. Below is a structured chapter-wise summary of essential concepts, numerical relations, and spatial structural insights.

1. Mole Concept & Stoichiometry

The mole connects microscopic particles to macroscopic quantities. Key relationship: \(n = \frac{m}{M} = \frac{N}{N_A} = \frac{V_{\text{STP}}}{22.4\text{ L}}\).

• Molarity (M): \(M = \frac{\text{moles of solute}}{\text{Volume of solution in L}}\)
• Molality (m): \(m = \frac{\text{moles of solute}}{\text{Mass of solvent in kg}}\)

2. Chemical Thermodynamics

First Law of Thermodynamics: \(\Delta U = q + w\), where expansion work is given by \(w = -P_{\text{ext}}\Delta V\).

• Enthalpy: \(H = U + PV\)
• Gibbs Free Energy: \(\Delta G = \Delta H - T\Delta S\). Spontaneity requires \(\Delta G < 0\).

3. Chemical & Ionic Equilibrium

For a reversible process, the equilibrium constant ratio is expressed as \(K_p = K_c(RT)^{\Delta n_g}\).

The pH of a standard acidic buffer solution is derived via the Henderson-Hasselbalch equation: \(\text{pH} = \text{pK}_a + \log\bigl(\frac{[\text{Salt}]}{[\text{Acid}]}\bigr)\).

4. Electrochemistry

Cell potential under non-standard conditions follows the Nernst Equation: \(E_{\text{cell}} = E^\circ_{\text{cell}} - \frac{0.0591}{n}\log Q\) at 298 K.

Kohlrausch's Law of Independent Migration: \(\Lambda_m^0 = A\lambda_+^0 + B\lambda_-^0\).

5. Spatial Structure in Physical & Organic Interfaces

Understanding structural geometry is vital when analyzing reactant stereochemistry in physical kinetics and equilibrium mechanisms. Consider the following structure representing a substituted cycloalkane intermediate:

```smiles CC1CCC(C)CC1 ```