Important Chemistry Formulas For NEET 2027 Exam- Topic-wise Formulas PDF

NEET 2027 Chemistry Formula Sheet PDF Download

Chemistry can feel like a memory test sometimes, but with the right direction, it doesn’t have to. Most questions of Chemistry in NEET are formula-based, mainly in Physical Chemistry, and being able to recall the right equation at the right time makes all the difference. Whether you're attempting NEET Chemistry previous years' questions, revising a few hours before your test, solving a mock, or flipping through notes on the go, this is the kind of list that helps you stay focused and score better.

Aspirants can download the NEET Chemistry formula PDF to cover the NEET Chemistry syllabus from here. This formula sheet PDF is designed for quick and clear revision. No extra theory, no unnecessary details, just what is needed to solve MCQs accurately and with confidence. Each section includes important formulas of NEET Chemistry 2027, short explanations, and smart tips that make last-minute learning smoother.

Download Here - NEET 2027 Chemistry Formula PDF

NEET Chemistry Constants, Units and Conversion Factors to Memorise

Learning constants with their units and conditions can help reduce errors in numerical questions. The following values are useful for revision.

NEET 2027 Physical Chemistry Formula

NEET Physical Chemistry is an important part of the syllabus. Knowing key formulas helps in solving problems quickly and accurately. These formulas cover topics like atomic structure, thermodynamics, and chemical equilibrium.

Atomic Structure

The atomic structure often forms the foundation for many conceptual questions. These formulas help relate energy, wavelength, and the motion of electrons in atoms.

Planck's Quantum Equation relates the energy of a photon to its frequency or wavelength:
E=h=hc
de Broglie’s Equation gives the relation between wavelength and momentum for any moving particle:
=hmv
Einstein's Photoelectric Equation explains how light energy is used to eject electrons:
h=h0+12mv2
Bohr’s Quantisation of Angular Momentum states that the angular momentum of an electron is quantised in integral multiples of $\frac

Heisenberg Uncertainty Principle

The Heisenberg Uncertainty Principle states that we cannot precisely know both the position and the momentum of a particle at the same time:

Heisenberg's Uncertainty Principle

`xph4`

If momentum is expressed as p=mv, the uncertainty relation becomes:

`xvh4m`

Quantum Numbers

Each electron in an atom is described by a unique set of four quantum numbers.

Principal quantum number (n) defines the main energy level or shell:

`n=1,2,3,`

Azimuthal quantum number (l) defines the subshell or shape of the orbital:

`l=0,1,2,,n-1`

Magnetic quantum number (ml) defines the orientation of the orbital in space:

`ml=-l,-(l-1),,0,,+(l-1),+l`

Spin quantum number (ms) defines the spin orientation of the electron:

`ms=+12or-12`

Thermodynamics: Most Useful Formulas

Thermodynamics is full of concepts, but in NEET, most questions are numerical. So focus on these formulas:

First Law of Thermodynamics relates internal energy, heat, and work:

`U=q+w`

Work Done During Isothermal Expansion of an ideal gas:

`w=-nRTV2V1`

Work Done in an Adiabatic Process can be expressed in two ways:

`w=P1V1-P2V2-1`

or

`w=nR(T1-T2)-1`

Difference Between Heat Capacities at constant pressure and constant volume:

`Cp-Cv=R`

The ratio of heat capacities is:

`=CpCv`

Enthalpy Change is related to internal energy and the change in moles of gaseous substances:

`H=U+ngRT`

Gibbs Free Energy Change indicates spontaneity and is linked to enthalpy and entropy:

`G=H-TS`

The relationship between standard Gibbs free energy change and the equilibrium constant is:

`G=-RTK`

Chemical Kinetics: Formulas to Save Time

Speed-based questions in NEET are usually direct and formula-driven. Focus on these:

The rate of a chemical reaction is defined as the change in concentration of reactants or products per unit time:

Rate of Reaction
Rate=-d[R]dt=d[P]dt
Integrated Rate Law for a First-Order Reaction
k=2.303t[R]0[R]t
Half-Life of a First-Order Reaction
t1/2=0.693k
The half-life of a first-order reaction is independent of the initial concentration.
Units of Rate Constant
- First order: s-1
- Second order: Lmol-1s-1
Arrhenius Equation
k=Ae-EaRT
or
k=A-EaRT

Chemical Equilibrium: Quick Recall Formulas

Equilibrium Constant
Kc=[C]c[D]d[A]a[B]b
For a reaction $aA + bB \rightleftharpoons cC + dD$, where the concentrations are expressed in mol/L.
Relation Between Kp and Kc
Kp=Kc(RT)n
where n=(c+d)-(a+b), considering only gaseous products and reactants.
Reaction Quotient
Qc=[C]c[D]d[A]a[B]b
Here, Qc uses the concentrations at any given moment, while Kc uses the equilibrium concentrations.

Direction of Reaction

• If Q<K, the forward reaction proceeds.
• If Q>K, the backward reaction proceeds.
• If Q=K, the system is at equilibrium.

Ionic Equilibrium: Strong vs Weak Electrolytes

Important for pH, Ka, and Kb-based questions.

pH and pOH relate to the concentration of hydrogen and hydroxide ions:

pH of a Solution
pH=-[H+]
pOH of a Solution
pOH=-[OH-]
Relationship Between pH and pOH
pH+pOH=14
Relationship Between Ka and Kb
The acid dissociation constant Ka and base dissociation constant Kb are related through the ionic product of water:
Kw=KaKb
$25^\circ\mathrm{C}$
pKa+pKb=14
Ostwald’s Dilution Law
For weak electrolytes, the degree of dissociation () is related to Ka and concentration (C):
=KaC
The exact relationship is:
Ka=C21-
Henderson–Hasselbalch Equation
For acidic buffer solutions, pH is expressed in terms of salt and acid concentrations:
pH=pKa+[Salt][Acid]

Solutions & Colligative Properties: Formulas for NEET 2027

This chapter has many numerical questions. Just knowing which formula to apply makes a huge difference.

Mole Fraction
The mole fraction of component A is the ratio of its moles to the total moles:
xA=nAnA+nB
Molality
Molality is the number of moles of solute per kilogram of solvent:
m=MolesofsoluteMassofsolvent(kg)
Molarity
Molarity is the number of moles of solute per litre of solution:
M=MolesofsoluteVolumeofsolution(L)
Henry’s Law
Gas pressure is proportional to its mole fraction in the solution:
p=KHx
Raoult’s Law
The vapour pressure of a solvent is proportional to its mole fraction:
PA=xAPA0
Relative Lowering of Vapour Pressure
For a solution containing a non-volatile solute:
PA0-PAPA0=xB
Elevation in Boiling Point
Tb=Kbm
Depression in Freezing Point
Tf=Kfm
Osmotic Pressure
=CRT
van’t Hoff Factor
The van’t Hoff factor accounts for the association or dissociation of solute particles:
i=ObservedcolligativepropertyCalculatedcolligativeproperty

Electrochemistry: NEET 2027 Formulas

The following NEET physical chemistry formulas cover electrolysis, cell potential, Gibbs energy and conductivity.

Faraday’s First Law of Electrolysis relates the mass of a substance deposited to the current and time:
W=ZIt
Alternatively,
W=EIt96500
Equivalent Mass
The equivalent mass is calculated using molar mass and the n-factor:
Equivalentmass=Molarmassn-factor
Relationship Between Standard Gibbs Energy and Cell Potential
G=-nFEcell
Relationship Between Standard Cell Potential and Equilibrium Constant (at 298 K)
K=nEcell0.0591
or
Ecell=0.0591nK
Nernst Equation
The Nernst equation gives the cell potential under non-standard conditions (298 K):
Ecell=Ecell-0.0591nQ
where the reaction quotient is
Q=aCcaDdaAaaBb
for the reaction $aA + bB \rightleftharpoons cC + dD$.
Here, aA, aB, aC, and aD represent the activities of the respective species, while a, b, c, and d are their stoichiometric coefficients. For dilute solutions, activities may be approximated by concentrations when appropriate. Pure solids and liquids are omitted from the reaction quotient.

NEET 2027 Organic Chemistry Formula

NEET Organic Chemistry deals with the structure, properties, and reactions of carbon compounds. Remembering key reactions and mechanisms is important for solving NEET questions. This section provides important formulas, reaction types, and patterns to help you revise quickly and accurately.

Organic Chemistry: Reaction Mechanisms & Named Reactions

This topic is all about pattern recognition in the NEET exam.
But still, here are some quick equations and key reactions:

General Formulas

IUPAC Naming Priority Order:
Carboxylic acid > Anhydride > Ester > Acid halide > Amide > Nitrile > Aldehyde > Ketone > Alcohol > Amine > Alkene > Alkyne > Alkane > Ether > Halide

Empirical formula:
Empirical formula = Percentage composition/atomic mass

Important Named Reactions

Aldol Condensation
$\text{Aldehyde/Ketone} \xrightarrow{\text{dil. base}} \beta\text{-hydroxy aldehyde/ketone} \xrightarrow{\Delta} \alpha,\beta\text{-unsaturated carbonyl compound}$
Cannizzaro Reaction
Aldehydes without an -hydrogen undergo disproportionation in the presence of a concentrated base. One molecule is oxidised to a carboxylate salt, while the other is reduced to an alcohol.
2RCHO+NaOHRCOONa+RCH2OH
Wurtz Reaction
$2\mathrm{R-X} + 2\mathrm{Na} \xrightarrow{\text{dry ether}} \mathrm{R-R} + 2\mathrm{NaX}$
Coupling of alkyl halides using sodium metal in dry ether.
Sandmeyer Reaction
$\mathrm{ArN_2^+X^-} \xrightarrow{\mathrm{CuX}} \mathrm{ArX} + \mathrm{N_2}\uparrow$
An aromatic diazonium salt is converted into an aryl halide using a cuprous halide.
Kolbe’s Electrolysis
2RCOO-R-R+2CO2+2e-
Decarboxylation and coupling of carboxylate ions during electrolysis produce an alkane.

NEET Organic Chemistry Named Reactions List and Reagents

Organic Chemistry requires students to understand reaction mechanisms, reagents and the conditions under which reactions occur. The NEET organic chemistry named reactions list below includes important reactions from the existing article and common reaction patterns.

Common Formula Mistakes in NEET Chemistry Numericals: Signs, Units and Conditions

The following NEET chemistry numericals common mistakes can lead to incorrect answers even when the correct formula is known.

1. Using the wrong work sign: With (\Delta U=q+w), work done on the system is positive. Work done by an expanding gas is negative under this convention.
2. Confusing equivalent mass and number of equivalents: Equivalent mass is molar mass divided by the n-factor. The number of equivalents is the given mass divided by equivalent mass, or moles multiplied by the n-factor.
3. Ignoring the change in gaseous moles: Use (\Delta H=\Delta U+\Delta n_gRT), where (\Delta n_g) is the gaseous product coefficient total minus the gaseous reactant coefficient total.
4. Mixing up (K_p) and (K_c): Use (K_p=K_c(RT)^{\Delta n_g}) for gaseous reactions, with (\Delta n_g) calculated from gaseous species only.
5. Confusing natural and common logarithms: Use (\ln x=2.303\log x) when converting between the two. Check which logarithm appears in the formula.
6. Mixing molarity and molality: Molarity uses the volume of the solution in litres; molality uses the mass of the solvent in kilograms.
7. Using temperature-specific constants at the wrong temperature: The 0.0591 V Nernst factor and (pH+pOH=14) apply at 298 K. Use the appropriate temperature-dependent expression when conditions differ.
8. Forgetting the van’t Hoff factor: Include (i) in colligative-property formulas when the solute dissociates or associates. Do not assume (i=1) for every solution.

How to Revise NEET Chemistry Formulas: Day-Wise Plan for Physical, Organic and Inorganic Chemistry

Formula sheets work best if the student uses them to try to recall formulas. This should be done according to a schedule and include questions related to formulas during every session.

Memorise Formulas by Saying and Writing

• Study a formula, understand its meaning, and write it down in memory.
• Compare it with the formulas you have in your notes, and consider the units, signs, and conditions.

Day-wise Revision Schedule

NEET 2027 Inorganic Chemistry Quick Revision

Inorganic Chemistry requires fewer equations and is more reliant on facts from NCERT textbooks, periodic trends, reactions, properties, and exceptions. Thus, rather than including redundant equations, students should focus on revising:

• Periodic trends and key exceptions
• Oxidation states
• Chemical bonding and geometry
• Coordination compounds and nomenclature
• Coordination number and oxidation state
• d- and f- Block elements
• Key reactions and compounds as per the syllabus

Based on the recent analysis of the NEET Chemistry paper of 2026 by Careers360, it was found that topics like Coordination Compounds, Hydrocarbons, d- and f-Block Elements, Chemical Bonding, and Thermodynamics are most important; however, chapter-wise trends should not be considered predictions for NEET 2027.

Combine Revision Habits with Common Study Mistakes

Do not keep reading the same sheet without actually testing yourself. Never skip any question that comes from a weak topic, and never memorise any formula without understanding where it is used. Maintain a small list of mistakes made while practising and go through those formulas again and again.

In the last week, you can use the NEET chemistry formulas PDF 2027 for your revision purposes. Pay more attention to the formulas that you tend to forget, constants and units, organic reactions, and inorganic trends and exceptions. Avoid using the formula sheet as an alternative to the syllabus or practice questions.