Complete Chemistry Formulas Guide

Master Chemistry Fundamentals

This comprehensive chemistry formula sheet contains all fundamental concepts that every Class 9 and 10 student must master. From chemical equations to mole calculations, these formulas are essential for understanding and solving chemistry problems effectively.

Expert Tip: Always balance chemical equations before calculations. Remember state symbols (s, l, g, aq) and practice writing formulas correctly.

1. Mole Concept & Stoichiometry

Basic Mole Formulas

Fundamental formulas for mole calculations and stoichiometric relationships.

Number of Moles

$$\text{n} = \frac{\text{m}}{\text{M}}$$

n = moles, m = mass (g), M = molar mass (g/mol)

Number of Particles

$$\text{N} = \text{n} \times \text{N}_\text{A}$$

Nₐ = Avogadro's number (6.02 × 10²³)

Molar Volume (STP)

$$\text{V} = \text{n} \times 22.4\ \text{L}$$

For gases at Standard Temperature & Pressure

Concentration Formulas

Formulas for calculating solution concentrations.

Molarity

$$\text{M} = \frac{\text{n}}{\text{V}}$$

n = moles, V = volume in liters

Molarity Alternative

$$\text{M} = \frac{\text{m}}{\text{M} \times \text{V}}$$

m = mass in grams

Mass Percentage

$$\text{Mass \%} = \frac{\text{mass of solute}}{\text{mass of solution}} \times 100$$

2. Gas Laws & Kinetic Theory

Gas Law Equations

Fundamental gas laws and their mathematical relationships.

Boyle's Law

$$\text{P}_1\text{V}_1 = \text{P}_2\text{V}_2$$

Constant temperature

Charles's Law

$$\frac{\text{V}_1}{\text{T}_1} = \frac{\text{V}_2}{\text{T}_2}$$

Constant pressure (T in Kelvin)

Ideal Gas Law

$$\text{PV} = \text{nRT}$$

R = 0.0821 L·atm/mol·K

Combined Gas Law

$$\frac{\text{P}_1\text{V}_1}{\text{T}_1} = \frac{\text{P}_2\text{V}_2}{\text{T}_2}$$

3. Chemical Reactions & Equations

Types of Chemical Reactions

Common chemical reaction patterns and their general equations.

Reaction Type	General Equation	Example
Combination	A + B → AB	2H₂ + O₂ → 2H₂O
Decomposition	AB → A + B	2H₂O → 2H₂ + O₂
Single Displacement	A + BC → AC + B	Zn + 2HCl → ZnCl₂ + H₂
Double Displacement	AB + CD → AD + CB	AgNO₃ + NaCl → AgCl + NaNO₃
Combustion	CₓHᵧ + O₂ → CO₂ + H₂O	CH₄ + 2O₂ → CO₂ + 2H₂O

Important Chemical Formulas

Common chemical compounds and their formulas.

Water

H₂O

Carbon Dioxide

CO₂

Sulfuric Acid

H₂SO₄

Hydrochloric Acid

HCl

Sodium Chloride

NaCl

Calcium Carbonate

CaCO₃

4. Acids, Bases & Salts

pH Calculations

Formulas for acidity and basicity calculations.

pH Formula

$$\text{pH} = -\log[\text{H}^+]$$

[H⁺] = hydrogen ion concentration

pOH Formula

$$\text{pOH} = -\log[\text{OH}^-]$$

pH + pOH Relationship

$$\text{pH} + \text{pOH} = 14$$

At 25°C (room temperature)

Neutralization Reactions

General equation for acid-base neutralization.

Acid + Base → Salt + Water

HCl + NaOH → NaCl + H₂O

5. Electrochemistry

Electrochemical Formulas

Formulas related to electrolysis and electrochemical cells.

Faraday's First Law

$$\text{m} = \text{Z} \times \text{I} \times \text{t}$$

m = mass deposited, Z = electrochemical equivalent

Faraday's Constant

$$\text{F} = 96500\ \text{C/mol}$$

Charge of 1 mole of electrons

6. Periodic Table & Atomic Structure

Atomic Structure Formulas

Fundamental formulas for atomic calculations.

Atomic Mass Unit

$$1\ \text{amu} = \frac{1}{12}\ \text{mass of C-12 atom}$$

Mass Number

$$\text{A} = \text{Z} + \text{N}$$

A = mass number, Z = protons, N = neutrons

Isotopic Abundance

$$\text{Avg. Atomic Mass} = \sum (\text{fraction} \times \text{mass})$$

7. Organic Chemistry Basics

Hydrocarbon Formulas

General formulas for organic compounds.

Compound Class	General Formula	Example
Alkanes	CₙH₂ₙ₊₂	CH₄ (Methane)
Alkenes	CₙH₂ₙ	C₂H₄ (Ethene)
Alkynes	CₙH₂ₙ₋₂	C₂H₂ (Ethyne)
Alcohols	CₙH₂ₙ₊₁OH	CH₃OH (Methanol)
Carboxylic Acids	CₙH₂ₙ₊₁COOH	CH₃COOH (Acetic acid)

Chemistry Study Strategies

1. Practice Balancing Equations

Start with simple equations and gradually move to complex ones. Always verify atom count on both sides.

2. Understand Mole Concept

Master mole calculations first. This is the foundation for most stoichiometry problems.

3. Memorize Common Formulas

Create flashcards for important chemical formulas and reaction patterns.

4. Regular Revision

Chemistry requires frequent review. Schedule short daily revision sessions.

Chemistry Study Tools

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Practice Reactions

Write and balance chemical equations daily

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Lab Safety Rules

Memorize important laboratory safety guidelines

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Stoichiometry Problems

Solve mole and concentration calculations

Print this page for quick reference during study sessions