Important Chemistry Formulas For NEET 2025 Exam- Topic-wise Formulas PDF

Important Chemistry Formulas for NEET: Are you studying for the NEET UG 2025 examination and looking to get admission in one of the best medical colleges in India? Chemistry is among the most important subjects in NEET, and a lot of questions are actually formula-based. Familiarity with these formulas can help you solve questions faster and with greater accuracy. Since the NEET 2025 exam is on 4th May 2025, now is the ideal time to practice and tighten your hold on important concepts of Physical, Organic, and Inorganic Chemistry.

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This Story also Contains

1. Chemistry Formula Sheet for NEET PDF 2025
2. Shapes Of Molecules
3. Solubility And Solubility Products
4. The Gas Laws- Boyle’s Law (Pressure-Volume Relationship)
5. Mathematical Analysis of Cubic System
6. Charge On Colloids
7. Oxidation State
8. Preparation Of Aldehyde
9. Nucleophilic Addition Reaction
10. Reduction And Oxidation Reaction
11. Chemical Properties Of Carboxylic Acid
12. Carbohydrates

In this article, topic-wise, the NEET Chemistry Formula Sheet PDF 2025 is compiled, containing all the major equations and reactions you should memorize. These formulas are carefully chosen to make sure that aspirants score better in the exam with smart effort. Be it last-minute revision or practicing mock tests, this formula sheet will improve speed, accuracy, and confidence. Download the PDF and improve NEET Chemistry preparation today!

Chemistry Formula Sheet for NEET PDF 2025

Given below are the important formulas for chemistry, divided as per the topics. Students can go through these to improve their chances of scoring better in NEET 2025 Exam.

1. Shapes Of Molecules

The ideal shapes of molecules, which are predicted based on electron pairs and lone pairs of electrons, are mentioned in the table below:

2. Solubility And Solubility Products

General Representation

AₓBᵧ ⇌ xAʸ⁺ + yBˣ⁻ Ksp = [Aʸ⁺]ˣ × [Bˣ⁻]ʸ

Relation between Solubility (s) and Solubility Product (Ksp):

AₓBᵧ ⇌ xAʸ⁺ + yBˣ⁻ (s → xs, ys)

Ksp = xˣ yʸ sˣ⁺ʸ

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3. The Gas Laws- Boyle’s Law (Pressure-Volume Relationship)

Boyle’s law may be expressed mathematically as:
P ∝ 1/V (at constant T and n)
or
V ∝ 1/P (at constant T and n)

Where:
T = temperature
P = pressure of the gas
n = number of moles of the gas
V = volume of the gas

⇒ V = k₁ × 1/P

Here, k₁ is the proportionality constant whose value depends upon the following factors.

Alternate Forms of Boyle’s Law

P₁V1 = P2V2 = constant
or
PV = K₁
or

P1/P2 = V2/V1
P₁ / P₂ = V₂ / V₁

4. Mathematical Analysis of Cubic System

Coordination Number (C. No.)

In Simple Cubic (SC): 6

In Face Centered Cubic (FCC): 12

In Body Centered Cubic (BCC): 8

Density of Lattice Matter (d)

It is the ratio of mass per unit cell to the total volume of a unit cell, and it is found out as follows.

d=Z × Atomic weight N0 × Volume of unit cell (a3)

Here, d = Density

Z = Number of atoms

N0 = Avogadro number

a³ = Volume

a = Edge length

To find the density of a unit cell in cm3, m must be taken in g/mole and should be in cm.

Radius Ratio

It is the ratio of the radius of an octahedral void to the radius of the sphere forming the close-packed arrangement. Normally, ionic solids are more compact, as voids are also occupied by cations (which are smaller in size). The pattern of arrangements and type of voids both depend on the relative size (ionic size) of two ions in a solid.

For example, when r+ = r-, the most probable and favourable arrangement is the BCC type.

With the help of relative ionic radii, it is easier to predict the most probable arrangement. This property is expressed as a radio ratio.

Radius ratio =r + (radius of cation )r − (Radius of anion)

From the value of the radius ratio, it is clear that the larger the radius ratio, the larger the size of the cation, and the more anions needed to surround it — that is, the more coordination numbers.

Radius ratio for tetrahedron

Angle ABC is the tetrahedral angle of 109.5^∘

∠ABD = 109.52 = 5475
In triangle ABD
Sin ABD = 0.8164 = AD/AB
or r∗ + rr = 10.8164 = 1.225
or r∗r = 0.225

Radius ratio for octahedron

AB = r⁺ + r
BD = r
∠ABC = 45°

In triangle ABD:
Cos(∠ABD) = 0.7071 = BD / AB = r / (r⁺ + r)

So,
(r⁺ + r) / r = 1 / 0.7071 = 1.414

Therefore,
r⁺ / r = 1.414 − 1 = 0.414

5. Charge On Colloids

Colloidal particles always carry an electric charge. The nature of this charge is the same for all the particles in a given colloidal solution and may be either positive or negative.

6. Oxidation State

An interesting feature in the variability of oxidation states of the d-block elements is noticed among the groups. Although in the p–block the lower oxidation states are favoured by the heavier members (due to the inert pair effect), the opposite is true in the groups of d-block.

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7. Preparation Of Aldehyde

Rosenmund Reduction

Stephen Reduction

8. Nucleophilic Addition Reaction

(i) Mechanism of nucleophilic addition reactions:

9. Reduction And Oxidation Reaction

Reduction to hydrocarbons
The carbonyl group of aldehydes and ketones is reduced to the CH2 group on treatment with zinc amalgam and concentrated hydrochloric acid (Clemmensen reduction) hydrazine hydrazone or with hydrazine, followed by heating with sodium or potassium hydroxide in a high boiling solvent such as ethylene glycol (Wolff-Kishner reduction).

Oxidation
Aldehydes differ from ketones in their oxidation reactions. Aldehydes are easily oxidised to carboxylic acids on treatment with common oxidising agents like nitric acid, potassium permanganate, potassium dichromate, etc. Even mild oxidising agents, mainly Tollens’ reagent and Fehlings’ reagent, also oxidise aldehydes.

10. Chemical Properties Of Carboxylic Acid

Formation of Anhydride

Reaction with Ammonia

Reduction

Decarboxylation

Kolbe's electrolysis
Halogenation

Ring substitution

11. Carbohydrates

Carbohydrates -

These are polyhydroxy aldehydes, ketones or substances that form these on hydrolysis and possess at least one chiral atom. The (-OH) group is available in the form of hemiacetals or hemiketals.

Classification

Carbohydrates can be classified into three categories:

1. Monosaccharides: They are the simplest carbohydrates, which cannot be hydrolysed into smaller molecules. They are sweet and crystalline and are called sugars.

2. Oligosaccharides: These carbohydrates, on hydrolysis, give two to nine molecules of monosaccharides classified as di-, tri, tetra-saccharides, etc. For example, sucrose, maltose, lactose, raffinose, etc. They are also called sugars.

3. Polysaccharides: These carbohydrates, on hydrolysis, give a large number of monosaccharides, e.g., starch, cellulose, etc. They are also called non-sugars.

Reducing and Non-Reducing Sugars
Those sugars which reduce Fehling's and Tollens's solutions are called reducing sugars and those which do not reduce these reagents are called non-reducing sugars.

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