IGCSE Chemistry Tutor UAE 2026 — Mole Concept, Organic Chemistry and Paper 6 Practicals Guide
IGCSE Chemistry (Cambridge 0620) is the second most tutored IGCSE science subject in UAE — and the one that covers the widest academic breadth, from atomic structure and bonding at the beginning of Year 10 to organic chemistry and stoichiometry at the end of Year 11. This guide covers the full paper structure, the five highest-demand topics, mole calculation technique, organic chemistry requirements, and Paper 6 practical knowledge.
IGCSE Chemistry Paper Structure — Cambridge 0620
|
Paper |
Format |
Duration |
% of Grade |
|
Paper 1 |
40 MCQ — Core
and Extended content |
45 minutes |
30% |
|
Paper 2 |
Structured
questions — Extended content |
1 hour 15
minutes |
50% |
|
Paper 6 |
Alternative to
Practical — written practical knowledge paper |
1 hour |
20% |
|
The A* grade
boundary in Cambridge IGCSE Chemistry typically requires approximately 90%+
of UMS marks. Paper 6 is the most coachable paper — it tests specific
practical techniques that can be systematically learned through targeted
preparation. |
Topic 1 — The Mole Concept: The Most-Requested IGCSE Chemistry Topic
The mole concept is the backbone of IGCSE Chemistry calculations. UAE students consistently request tutoring on this topic more than any other in Chemistry. The three fundamental mole equations:
• Moles from mass: moles = mass (g) ÷ molar mass (g/mol). Molar mass is calculated from the periodic table by adding atomic masses for each element.
• Moles in solution: moles = volume (dm³) × concentration (mol/dm³). Note: 1 dm³ = 1000 cm³; volumes in cm³ must be divided by 1000 before use.
• Moles of gas at RTP: moles = volume (dm³) ÷ 24. At Room Temperature and Pressure (25°C, 1 atm), 1 mole of any gas occupies 24 dm³.
Stoichiometry — Using Mole Ratios From Balanced Equations
Once the mole concept is secure, stoichiometry uses the coefficients in a balanced equation as mole ratios. Process: (1) write and balance the equation; (2) calculate moles of the given substance; (3) use the mole ratio to find moles of the target substance; (4) convert moles back to mass, volume, or concentration as required. This four-step process applies to every stoichiometry question regardless of context.
Topic 2 — Organic Chemistry: Reaction Types and Conditions
|
Organic Class |
Key Reactions |
Conditions /
Reagents |
Test /
Evidence |
|
Alkanes (e.g.
methane, CH₄) |
Combustion
(complete and incomplete); Substitution with halogens |
UV light for
halogenation; excess O₂ for complete combustion |
Substitution
is slow in dark, fast in UV — shows free radical mechanism |
|
Alkenes (e.g.
ethene, C₂H₄) |
Addition of
H₂; Addition of Cl₂/Br₂; Addition of H₂O (hydration); Polymerisation |
Ni catalyst
for hydrogenation; steam/H₃PO₄ catalyst for hydration |
Bromine water
decolourises — distinguishes from alkanes |
|
Alcohols (e.g.
ethanol, C₂H₅OH) |
Combustion;
Oxidation to carboxylic acid; Dehydration to alkene; Esterification |
K₂Cr₂O₇/H₂SO₄
for oxidation; Al₂O₃ catalyst for dehydration |
Acidified
potassium dichromate changes from orange to green on oxidation |
|
Carboxylic
acids (e.g. ethanoic acid) |
Reaction with
metals, bases, carbonates; Esterification with alcohols |
Acid + alcohol
+ concentrated H₂SO₄ catalyst; heat for esterification |
Produces
fruity smell for esters; CO₂ with carbonates |
Topic 3 — Electrochemistry: Electrolysis and Electrode Equations
Electrolysis questions appear in almost every IGCSE Chemistry Paper 2 and are a consistent mark-losing area. Students must know:
• At the cathode (negative electrode): cations (positive ions) are attracted and gain electrons (reduction). In aqueous solutions: if the cation is below hydrogen in the reactivity series, the cation is discharged; if above, hydrogen is discharged instead.
• At the anode (positive electrode): anions (negative ions) are attracted and lose electrons (oxidation). In aqueous solutions: if halide ions are present, they are preferentially discharged; otherwise oxygen is discharged from water.
• Writing electrode equations: always balance the number of electrons. Example: Cu²⁺ + 2e⁻ → Cu (cathode, copper plating)
Topic 4 — Rates of Reaction and Collision Theory
Rate of reaction questions require explaining how each factor increases collision frequency or increases activation energy being exceeded. The five factors:
|
Factor |
Effect on
Rate |
Collision
Theory Explanation |
|
Concentration
increase |
Rate increases |
More particles
per unit volume → more frequent collisions between reactant particles |
|
Temperature
increase |
Rate increases
significantly |
Higher
temperature → particles move faster → more frequent collisions AND higher
proportion of collisions exceed activation energy |
|
Surface area
increase (particle size decrease) |
Rate increases |
More surface
area exposed → more particles at surface available for collision |
|
Catalyst |
Rate increases |
Provides an
alternative reaction pathway with lower activation energy → greater
proportion of collisions result in reaction |
|
Pressure
increase (gases) |
Rate increases |
More particles
per unit volume → same effect as increasing concentration |
Topic 5 — Paper 6 Practical Knowledge (Alternative to Practical)
Paper 6 tests knowledge of specific practical techniques as written questions — no actual lab work required. Essential practical scenarios UAE students must know:
• Titration technique: burette reading (to 2 d.p., reading from the bottom of the meniscus); recording titre values; calculating average titre; identifying anomalous results
• Qualitative analysis — flame tests: Li = crimson; Na = yellow; K = lilac; Ca = brick-red; Cu = green-blue
• Qualitative analysis — precipitate tests: add NaOH solution to identify metal cations by precipitate colour (Fe²⁺ = green; Fe³⁺ = brown; Cu²⁺ = blue; NH₄⁺ — warm gently, test gas with damp red litmus turning blue)
• Gas tests: CO₂ (turns limewater milky); H₂ (squeaky pop with lighted splint); O₂ (relights glowing splint); Cl₂ (bleaches damp litmus paper); NH₃ (turns damp red litmus blue; pungent smell)
• Chromatography: calculating Rf values = distance moved by substance ÷ distance moved by solvent front; identifying substances by comparing Rf values to known standards
|
EdFlik IGCSE
Chemistry tutors are Cambridge 0620 specialists. Sessions use past papers,
mark schemes, and Paper 6 practical scenario practice including mole
calculations, organic reactions, and electrolysis. From AED 60. Free
diagnostic trial. Book at www.edflik.com or WhatsApp +91 88788 96600. |
Frequently Asked Questions
Q: Is IGCSE Chemistry hard?
One of the most demanding IGCSE sciences. Main challenges: mole concept and stoichiometry, organic chemistry reaction types (with conditions), and Paper 6 practical knowledge. Past paper drilling with mark schemes produces the fastest grade improvement.
Q: What is the mole concept in IGCSE Chemistry?
moles = mass ÷ molar mass; moles = volume (dm³) × concentration; moles = volume of gas ÷ 24 at RTP. Stoichiometry uses mole ratios from balanced equations to calculate masses, volumes, and concentrations.
Q: What organic chemistry do I need to know for IGCSE?
Alkanes (combustion, halogenation), alkenes (addition reactions, bromine water test), alcohols (combustion, oxidation, esterification), and carboxylic acids (reactions with metals, bases, and alcohols). Each class requires knowing structure, naming, properties, and key reactions with conditions.
Q: How many papers does IGCSE Chemistry have?
Most UAE students sit Papers 1 (30%), 2 (50%), and 6 (20%). Paper 1 is MCQ, Paper 2 is Extended structured questions, Paper 6 is Alternative to Practical.
Q: What are the most difficult IGCSE Chemistry topics for UAE students?
Mole calculations and stoichiometry, organic chemistry reaction types, electrolysis and electrode equations, rates of reaction with collision theory explanations, and reversible reactions and equilibrium.
