NEET UG 2026: Chemistry Formula Sheet FREE PDF Download

Physical chemistry deals with the physical properties and behavior of chemical systems. Some of the important formulas in physical chemistry include:

1. Gas laws: ${PV = nRT}$ (ideal gas law), ${\dfrac{{PV}}{T} = k}$ (Gay-Lussac's law), ${\dfrac{{P1V1}}{{T1}} = \dfrac{{P2V2}}{{T2}}}$ (Boyle's law and Charles' law).

2. Thermodynamics: ${\Delta G = \Delta H - T\Delta S}$  (Gibbs free energy equation), ${\Delta H = q + P\Delta V}$ (enthalpy equation).

3. Electrochemistry: ${{{Ecell = }}{{{E}}^ \circ }{{cell}} - \left( {\dfrac{{0.0592}}{n}} \right)\log Q}$ (Nernst equation), ${\Delta {G^ \circ } =  - nF{E^ \circ }{{cell}}}$ (Gibbs free energy equation for electrochemical reactions).

List of Organic Chemistry Formulas for NEET UG 2026

Organic chemistry deals with the study of carbon-based compounds and their reactions. Some important formulas in organic chemistry include:

1. Isomerism: ${{C_n}{H_{2n + 2}}}$ (alkanes), ${{C_n}{H_{2n}}}$ (alkenes), ${{C_n}{H_{2n - 2}}}$ (alkynes).

2. Hydrocarbons: ${{C_n}{H_{2n + 2}}}$ (alkanes), ${{C_n}{H_{2n}}}$ (alkenes), ${{C_n}{H_{2n - 2}}}$ (alkynes), ${{C_n}{H_{2n - 4}}}$ (arenes).

3. Functional groups: $R-OH$ (alcohols), $R-COOH$ (carboxylic acids), ${R - N{H_2}}$ (amines).

List of Inorganic Chemistry Formulas for NEET 2026

Inorganic chemistry deals with the study of non-carbon-based compounds and their reactions. Some important formulas in inorganic chemistry include:

1. Coordination compounds: ${\left[ {M\left( {{H_2}O} \right)n} \right]x + nL \to \left[ {M\left( {{H_2}O} \right)mLn} \right]x + }$ (formation of a complex ion), ${{{CFT:}}\Delta {{o = 10Dq}}}$ (crystal field theory equation).

2. Electrochemistry: $E^\circ_{\text{cell}} = E^\circ_{\text{reduction}} - E^\circ_{\text{oxidation}}$

$\Delta G^\circ = -nF E^\circ_{\text{cell}}$

(Gibbs free energy equation for electrochemical reactions)

Here are some important formulas related to polymers that are relevant for NEET chemistry:

• Degree of Polymerization (DP): The degree of polymerization is the number of monomers in a polymer chain. It is calculated using the formula:

$\text{DP} = \dfrac{\text{Molecular weight of polymer}}{\text{Molecular weight of monomer}}$

• Polymerization Reaction: Polymerization is the process of creating polymers by combining monomers. The general formula for polymerization is:

${n\left( {C{H_2} = C{H_2}} \right) \to \left( { - C{H_2} - C{H_2} - } \right)n}$

This formula represents the polymerization of ethylene ${\left( {C{H_2} = C{H_2}} \right)}$ to form polyethylene ${\left( { - C{H_2} - C{H_2} - } \right)n}$.

• Repeat Unit: The repeat unit is the smallest unit that repeats in a polymer chain. It is important to identify the repeat unit to determine the structure and properties of the polymer. The formula for the repeat unit is determined by the monomer used in the polymerization reaction.

• Polydispersity Index (PDI): The polydispersity index is a measure of the molecular weight distribution of a polymer. It is calculated using the formula:

${{{PDI = }}\dfrac{{M_w}}{{M_n}}}$

Where $M_w$ is the weight average molecular weight and $M_n$ is the number average molecular weight.

• Tacticity: Tacticity refers to the arrangement of side groups on the polymer chain. The three types of tacticity are isotactic, syndiotactic, and atactic. The formula for the tacticity of a polymer depends on the monomer used and the arrangement of the side groups

List of Ionic Equilibrium Formulas for NEET

The study of ionic equilibrium involves the use of a variety of formulas, which are used to calculate various properties of solutions containing ionic compounds. Some of the important formulas used in the study of ionic equilibrium include:

1. Ionic Product of Water: The ionic product of water is a measure of the concentration of the hydrogen ions and hydroxide ions in a solution. The formula for the ionic product of water is $K_w = [H^+][OH^-]$, where Kw is the ionic product of water, $[H^+]$ is the concentration of hydrogen ions, and $[OH^-]$ is the concentration of hydroxide ions.

2. Acid Dissociation Constant: The acid dissociation constant, also known as $K_a$, is a measure of the strength of an acid. The formula for $K_a$ is ${K_a = \dfrac{{\left[ {H^+ } \right]\left[ {A^-} \right]}}{{\left[ {H_A} \right]}}}$ , where $[H^+]$ is the concentration of hydrogen ions, $[A^-]$ is the concentration of the conjugate base, and $[H_A]$ is the concentration of the acid.

3. Base Dissociation Constant: The base dissociation constant, also known as $K_b$, is a measure of the strength of a base. The formula for $K_b$ is ${Kb = \dfrac{{\left[ {BH^+ } \right]\left[ {OH^- } \right]}}{{\left[ B \right]}}}$, where $[BH^+]$ is the concentration of the conjugate acid, $[OH^-]$ is the concentration of hydroxide ions, and $[B]$ is the concentration of the base.

4. pH: The pH is a measure of the acidity or basicity of a solution and is defined as the negative logarithm of the hydrogen ion concentration. The formula for pH is ${pH =  - \log \left[ {H^+ } \right]}$.

5. pOH: The pOH is a measure of the concentration of hydroxide ions in a solution and is defined as the negative logarithm of the hydroxide ion concentration. The formula for ${pOH}$ is ${pOH =  - \log \left[ {OH^- } \right]}$.

Chemical Equilibrium

The state in which a chemical reaction's forward and reverse rates are equal is known as chemical equilibrium. To put it another way, this is the point at which the concentrations of the reactants and products stay the same over time.

The product and reactant concentrations at equilibrium are related by the equilibrium constant (Kc), a numerical value. The articulation for Kc is gotten from the fair substance condition for the response and addresses the proportion of the groupings of the items to the centralizations of the reactants at harmony.

The factors that affect chemical equilibrium include temperature, pressure, and concentration. Le Chatelier's guideline is utilized to foresee the course wherein a compound harmony will move in light of changes in these variables. For example, if the concentration of a reactant is increased, the reaction will shift in the direction that consumes that reactant, thus producing more products.

Class 11 Physical Chemistry: Chemical Equilibrium

Equilibrium Constant Expressions
For a reaction: aA + bB ⇌ cC + dD

Kc = [C]ᶜ [D]ᵈ / [A]ᵃ [B]ᵇ

Kc uses concentration in mol/L

Kp = (P_C)ᶜ (P_D)ᵈ / (P_A)ᵃ (P_B)ᵇ

Kp uses partial pressures in atm

Relation Between Kp and Kc
Kp = Kc (RT)^Δn

Where:

• Δn = (c + d) − (a + b)

• Δn = moles of gaseous products − moles of gaseous reactants

Class 11 Physical Chemistry: Ionic Equilibrium

pH, pOH, and pKa Relations

• pH = −log[H⁺]

• pOH = −log[OH⁻]

• pH + pOH = 14 (at 25°C)

• pKa = −log(Ka)

• pKb = −log(Kb)

• pKa + pKb = 14 (for conjugate acid-base pair)

Henderson-Hasselbalch Equation

For buffer solutions:
pH = pKa + log([A⁻] / [HA])

For basic buffer:
pOH = pKb + log([B] / [BH⁺])

Ionisation Constants

For weak acid HA ⇌ H⁺ + A⁻:
Ka = [H⁺][A⁻] / [HA]

For weak base B + H₂O ⇌ BH⁺ + OH⁻:

Solubility Product Constant (Ksp)

For a salt AxBy ⇌ xAy⁺ + yBx⁻:
Ksp = [Ay⁺]ˣ [Bx⁻]ʸ

Gaseous State

The ideal gas law is one of the most fundamental formulas in the study of gaseous state. It is given by ${PV = nRT}$, where P is the pressure of the gas, V is its volume, n is the number of moles of the gas, R is the universal gas constant, and T is the temperature of the gas. This law can be used to calculate any of the variables involved in the formula as long as the others are known.

Another important formula is the Boyle's law, which states that, at a constant temperature and mole count, a gas's pressure is inversely proportional to its volume. This law is expressed mathematically as $PV = k$, where k is a constant.

The Charles' law, on the other hand, describes the relationship between the number of moles and a gas's volume at a constant pressure and temperature. It is given by ${\dfrac{V}{T} = k}$, where k is a constant.

According to Avogadro's law, a gas's volume is directly proportional to its mole count at constant temperature and pressure.. Mathematically, it is expressed as ${\dfrac{V}{n} = k}$, where k is a constant.

The Dalton's law of fractional tensions expresses that the all out strain of a combination of gases is equivalent to the amount of the incomplete tensions of each gas. The pressure that a gas would exert if it were the only gas in the container is known as its partial pressure.

Class 12 Organic Chemistry: Alcohols, Phenols, and Ethers

Preparation of Alcohols

• From alkenes: RCH=CH₂ + H₂O → RCH(OH)CH₃

• From carbonyl: RCHO + H₂ → RCH₂OH

• From Grignard: RMgX + HCHO → RCH₂OH + MgX(OH)

Reactions of Alcohols

• Oxidation: 1° → RCHO → RCOOH; 2° → RCOR'; 3° → No reaction

• Dehydration: R-OH → Alkene + H₂O

• With SOCl₂: R-OH + SOCl₂ → R-Cl + SO₂ + HCl

• Esterification: R-OH + R'COOH → R'COOR + H₂O

Phenols and Ethers

Phenols:

• More acidic than alcohols (pKa ≈ 10)

• Reactions: Electrophilic substitution (o,p-directing)

• Tests: FeCl₃ (violet color)

Class 11 Organic Chemistry: Alcohols, Phenols, and Ethers

1. Alcohols

• General formula: R-OH

Classification:

• Primary (1°): RCH₂-OH

• Secondary (2°): R₂CH-OH

• Tertiary (3°): R₃C-OH

Key reactions:

• Oxidation: 1° → Aldehyde → Acid; 2° → Ketone

• Dehydration: R-OH → Alkene + H₂O

• With HX: R-OH + HX → R-X + H₂O

2. Phenols

• Structure: Ar-OH (where Ar = aromatic ring)

Properties:

• More acidic than alcohols (pKa ≈ 10)

• Resonance stabilisation of phenoxide ion

Key reactions:

• With NaOH: C₆H₅OH + NaOH → C₆H₅ONa + H₂O

• Electrophilic substitution: bromination, nitration

• Kolbe's reaction: C₆H₅ONa + CO₂ → HOC₆H₄COOH

3. Ethers

• General formula: R-O-R'

Preparation:

• Williamson synthesis: R-X + R'O⁻Na⁺ → R-O-R' + NaX

• Dehydration of alcohols: 2R-OH → R-O-R + H₂O

Key reactions:

• With HI: R-O-R' + 2HI → R-I + R'-I + H₂O

• Auto-oxidation: Forms explosive peroxides (R-O-O-R)

Class 12 Physical Chemistry: Solutions

Concentration Terms

• Molarity (M) = Moles of solute / Volume of solution in litres

• Molality (m) = Moles of solute / Mass of solvent in kg

• Mole fraction (x) = Moles of component / Total moles

• Mass percentage = (Mass of solute / Mass of solution) × 100%

• Volume percentage = (Volume of solute / Volume of solution) × 100%

• Parts per million (ppm) = (Mass of solute / Mass of solution) × 10⁶

Colligative Properties Formulas

Relative lowering of vapour pressure:
(P⁰ − P) / P⁰ = n_B / (n_A + n_B) = x_B

Boiling point elevation:
ΔT_b = K_b × m × i

Freezing point depression:
ΔT_f = K_f × m × i

Osmotic pressure:
π = CRT

H2 - Class 12 Organic Chemistry: Haloalkanes and Haloarenes

Nucleophilic Substitution Reactions

SN1 mechanism:

1. R-X → R⁺ + X⁻ (slow)

2. R⁺ + Nu⁻ → R-Nu (fast)

SN2 mechanism:
Nu⁻ + R-X → [Nu---R---X] → Nu-R + X⁻

Common nucleophiles: OH⁻, OR⁻, NH₃, CN⁻, RS⁻

Elimination Reactions

E1 mechanism:

1. R-X → R⁺ + X⁻ (slow)

2. R⁺ → alkene + H⁺ (fast)

E2 mechanism:
Base + H-C-C-X → alkene + H⁺ + X⁻

Saytzeff rule: Major product is the more substituted alkene

Important Reaction Equations

Haloalkanes:

• R-X + OH⁻ → R-OH + X⁻ (hydrolysis)

• R-X + KCN → R-CN + KX (cyanation)

• R-X + NH₃ → R-NH₂ + HX (amination)

• R-X + Mg → R-Mg-X (Grignard reagent)

Haloarenes:

• ArX + Na → Ar-Ar + NaX (Wurtz-Fittig)

• ArX + Cu → Ar-Ar + CuX₂ (Ullmann)

• ArX + KNH₂ → Ar-NH₂ + KX (requires very strong conditions)

Also Check: NEET Physics Formulas

Conclusion

NEET chemistry formulas are crucial for success on the exam. By regularly practicing, understanding the concepts, using memory aids, and seeking help when needed, students can effectively memorize and apply these formulas to solve complex problems.

Additionally, students can also seek help from their teachers and peers to clarify any doubts or difficulties they may have in understanding the formulas and concepts related to ionic equilibrium. With consistent practice and effort, students can master the formulas and excel in NEET chemistry examinations.