🧪 IGCSE Chemistry Formula Sheet 2026

Complete Cambridge IGCSE Chemistry (0620) Formula Reference Guide

Cambridge IGCSE Chemistry 0620 Extended Syllabus

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Aligned with the latest 2026 syllabus and board specifications. This sheet is prepared to match your exam board’s official specifications for the 2026 exam series.

Essential IGCSE Chemistry Formulas & Concepts

Master your IGCSE Chemistry exams with our comprehensive formula sheet covering all essential formulas, concepts, and calculations for Cambridge IGCSE Chemistry (0620). This reference guide includes atomic structure, stoichiometry, energetics, rates of reaction, equilibrium, redox reactions, electrolysis, acids & bases, organic chemistry, and more.

⚛️ Atomic Structure
🧮 Chemical Calculations
Energetics & Reactions
🧪 Acids & Bases

CIE IGCSE Chemistry (0620) – Extended Syllabus Formula Sheet

Complete Reference Guide for 2026 Syllabus

1. Atomic Structure & Stoichiometry

Relative atomic mass
Ar = (average mass of 1 atom) / (1/12 mass of C-12 atom)
No unit
Relative molecular/formula mass
Mr = Σ Ar
No unit
Moles
n = mass / Mr
mass in g
Mass
mass = n × Mr
g
Number of particles
N = n × Nₐ
Avogadro's constant 6.02 × 10²³
Volume of gas (r.t.p.)
n = V / 24
V in dm³, n in mol
Concentration
C = n / V
mol/dm³, V in dm³
Percentage composition
(mass of element / mass of compound) × 100
%
Empirical formula
Simplest whole-number ratio of atoms
Use ratio of moles

2. Chemical Calculations

Relative Molecular Mass (Mr)
Sum of relative atomic masses (Ar)
No units
Moles (n)
n = mass / Mr
mass in g
Mass
mass = n × Mr
Number of particles
no. of particles = n × 6.02 × 10²³
Avogadro's constant
Moles from gas volume
n = volume of gas / 24
Volume in dm³ at r.t.p.
Concentration
concentration = moles / volume
mol/dm³
Percentage composition
(mass of element in compound / total mass of compound) × 100
Empirical formula
Simplest whole number ratio of atoms

2. Energetics

Energy change
Q = mcΔT
J, m in g, c = 4.2 J/g°C
Molar enthalpy change
ΔH = Q/n
kJ/mol
Exothermic
Energy released (ΔH negative)
Temp ↑
Endothermic
Energy absorbed (ΔH positive)
Temp ↓

3. Rates of Reaction

Rate of reaction
Rate = (change in concentration or mass) / time
mol/s or g/s
Factors affecting rate
Concentration, surface area, temperature, catalyst
Collision theory
Rate ∝ number of effective collisions

4. Equilibrium & Le Chatelier

Dynamic equilibrium
Rate forward = Rate backward
Closed system
Le Chatelier's principle
System opposes change in concentration, pressure, temperature
Exothermic: ↑T shifts left; Endothermic: ↑T shifts right

5. Gases & Gas Laws

Ideal gas equation
PV = nRT
P in Pa, V in m³, n in mol, R = 8.31 J/mol·K, T in K
Gas volume at r.t.p.
n = V / 24
V in dm³, n in mol

6. Acids, Bases & Salts

pH
pH = -log[H⁺]
Neutralisation
Acid + Base → Salt + Water
e.g., HCl + NaOH → NaCl + H₂O
Titration moles
n = C × V
C in mol/dm³, V in dm³

7. Electrolysis

Charge
Q = I × t
I in A, t in s
Moles of substance formed
n = Q / (F × z)
F = 96500 C/mol, z = electrons per ion

8. Redox & Reactivity

Reactivity series
K > Na > Ca > Mg > Al > Zn > Fe > Pb > H > Cu
Most reactive → least reactive
Extraction
Metal oxide + C → Metal + CO
e.g., Fe₂O₃ + 3C → 2Fe + 3CO

9. Organic Chemistry

Alkane
CₙH₂ₙ₊₂
Saturated hydrocarbon
Alkene
CₙH₂ₙ
Unsaturated hydrocarbon
Alcohol
CₙH₂ₙ₊₁OH
Functional group -OH
Combustion
Hydrocarbon + O₂ → CO₂ + H₂O
Complete combustion
Cracking
Long-chain → shorter-chain + alkene
Thermal or catalytic cracking

10. Units & Constants

Avogadro's constant
Nₐ = 6.02 × 10²³ mol⁻¹
Molar gas volume (r.t.p.)
24 dm³/mol
Specific heat capacity of water
c = 4.2 J/g°C
Faraday constant
F = 96500 C/mol
Volume conversion
1 dm³ = 1000 cm³

📚 How to Use This Chemistry Formula Sheet

🧪

Understand the Concepts

Don't just memorize formulas - understand the underlying chemical principles and how each formula relates to real chemical processes.

⚛️

Practice Calculations

Work through plenty of practice problems using these formulas. Chemistry calculations require both understanding and practice.

🔬

Connect Theory to Practice

Link these formulas to laboratory experiments and real-world chemical processes to deepen your understanding.

📝

Show Your Working

Always show your calculations step by step in exams. This helps you avoid mistakes and earns partial credit.

Formula sheet FAQ

Quick answers about this free PDF, how to use it for exam revision, and how it relates to your official syllabus.

Is the IGCSE Chemistry Formula Sheet 2026 free to download as a PDF?

Yes. This Tutopiya formula sheet is free to use and you can download it as a PDF from this page for offline revision. There is no payment or account required for the PDF download.

What Chemistry topics and equations does this formula sheet cover?

This page groups key Chemistry formulas in one place for revision. Complete IGCSE Chemistry formula sheet 2026 for Cambridge IGCSE Chemistry (0620). Essential formulas for atomic structure, stoichiometry, energetics, rates of reaction, equilibrium, redox, electrolysis, acids & bases,… Always cross-check with your official syllabus and past papers for your exam session.

Can I use this instead of the official exam formula booklet in the exam?

No. In the exam you must follow only what your exam board allows in the hall—usually the official formula booklet or data sheet where provided. This page is a revision and teaching aid, not a replacement for board-issued materials.

Who is this formula sheet for (Secondary)?

It is written for students preparing for assessments at Secondary in Chemistry, including classroom revision, homework support, and independent study. Teachers and tutors can also share it as a quick reference.

How should I revise with this formula sheet?

Work through past paper questions, quote the correct formula before substituting values, and check units and notation every time. Pair this sheet with timed practice and mark schemes so you see how examiners expect working to be set out.

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