Pearson Edexcel International GCSE in Chemistry · 4CH1

Chemistry

Everything is particles, and everything chemistry asks of you follows from what those particles are doing. These lessons make the invisible layer visible first — then the equations, the conditions and the calculations stop being arbitrary.

How the qualification is assessed

Two untiered papers. Paper 1 is 110 marks in 2 hours and covers the core content; Paper 2 is 70 marks in 1 hour 15 minutes and covers everything, including the bold C statements. Experimental skills are tested in written questions.

Incandio is aligned to this specification. It is not published by, endorsed by or affiliated with Pearson, and it reproduces none of Pearson's wording — the statement numbers are given so you can check every lesson against your own copy.

61 lessons across 4 topics

They cover 182 of the 182 statements on the specification.

Topic 1 · Principles of chemistry

The foundations everything else is built on: particles and states, separating mixtures, atomic structure, the Periodic Table, moles and equations, and the three types of bonding — plus electrolysis.

• The Three States of Matter — What the particles are doing in a solid, a liquid and a gas — and what really changes when ice melts.
• Pure Substances, Mixtures and How to Separate Them — Why a pure substance melts at one temperature, and which separation technique to reach for when.
• Inside the Atom — Protons, neutrons and electrons — where they are, what they weigh, what they carry, and how isotopes give an element a decimal mass.
• Electronic Configurations and the Periodic Table — Why the table has the shape it has: the group number IS the outer-shell electron count, and everything follows from that.
• Solubility and Solubility Curves — Why a solution can be full, why hot water holds more, and how one curve tells you exactly how many crystals you will get back.
• Formulae and Balanced Equations — Why the ash weighs more than the metal, what balancing an equation is really doing, and how to add up a formula mass without losing a bracket.
• The Mole — Chemists have to count atoms and can only weigh them. The mole is the one idea that turns a mass on a balance into a number of particles.
• Reacting Masses and Percentage Yield — How much product a reaction should give, how much it actually gives, and why the two are never the same.
• Empirical and Molecular Formulae — Working out a formula you were never told, from nothing but the masses on a balance.
• Concentration and Gas Volumes — Counting particles in a solution you can only measure by volume, and in a gas you cannot weigh at all.
• Ionic Bonding — Why atoms give electrons away or take them, how far you can predict that from the periodic table, and how to draw it.
• Ionic Structures and Their Properties — Why salt melts at 800 °C, why it will not conduct until it does, and why both facts come from the same lattice.
• Covalent Bonding — What two atoms do when neither can afford to give an electron away.
• Simple Molecular Substances — Strong bonds inside, feeble forces outside — and why that makes methane a gas.
• Giant Covalent Structures — The same element, the same bonds — and one form cuts glass while another marks paper.
• Metallic Bonding — A lattice of positive ions in a sea of electrons that belong to no atom in particular.
• Why Substances Conduct — the Four Structures Compared — One test applied to every structure in the topic, and the two words electrolysis is built on.
• Electrolysis — Using a current to pull a compound apart, and writing down what happens at each electrode.

Topic 2 · Inorganic chemistry

The behaviour of real substances: Group 1 and Group 7 trends, the gases in air, the reactivity series and rusting, extracting metals, acids and alkalis, salt preparation and the chemical tests.

• Group 1 — the Alkali Metals — Metals soft enough to cut with a knife, which set fire to water — and get worse as you go down.
• Group 7 — the Halogens — A green gas, a brown liquid and a grey solid — and a trend that runs the opposite way to Group 1.
• The Gases in the Air — Four gases, one of which is doing almost all the chemistry — and how to measure it without ever touching it.
• Combustion and Carbonates — Three things burning in oxygen, one carbonate breaking apart, and the 0.04% gas that changes the climate.
• The Reactivity Series — Putting eleven metals in order by watching what each one will and will not do.
• Rusting and its Prevention — Two things are needed to rust iron, and every method of stopping it removes one of them — or cheats.
• Redox — The same reaction described twice — once by what gains oxygen, and once by what loses electrons.
• Extracting Metals from their Ores — Where a metal sits in the reactivity series decides how much trouble it takes to get it out.
• Uses of Metals, and Alloys — Why each metal is used where it is — and why almost none of them is used pure.
• Acids, Alkalis and the pH Scale — Three indicators that answer a yes-or-no question, and one scale that answers 'how much'.
• Hydrogen Ions and Neutralisation — What every acid has in common, what every alkali has in common, and why every neutralisation is one equation.
• Titrations — Finding the exact volume that neutralises — and then making the salt again without the indicator in it.
• Solubility Rules and Proton Transfer — Which salts dissolve, and the broader definition of an acid that explains why ammonia counts.
• The Reactions of Acids — Three things acids react with, three sets of products, and one test that identifies a carbonate instantly.
• Preparing a Soluble Salt — Add too much on purpose, filter the excess away, and crystallise what is left.
• Preparing an Insoluble Salt — Mix two solutions, and the salt you want falls out of them as a solid.
• Tests for Gases, and for Water — Five gases, five tests — and the difference between something being water and being pure water.
• Flame Tests — Five metal ions that announce themselves by the colour they give a flame.
• Tests for Ions — Sodium hydroxide identifies four cations by the colour of what falls out — and three anion tests complete the set.

Topic 3 · Physical chemistry

Why reactions release or absorb energy, what controls how fast they go, and what happens when a reaction can run both ways and settles into equilibrium.

• Exothermic and Endothermic Reactions — Reactions that warm their surroundings and reactions that chill them — and why the thermometer tells you which.
• Calorimetry Calculations — Turning a temperature rise into an energy in joules, and then into a value per mole.
• Energy Diagrams and Bond Energies — Why breaking bonds costs energy, why making them repays it, and why the balance decides everything.
• Rates of Reaction — Four things that make a reaction faster, and two ways of measuring whether they did.
• Collision Theory — One explanation that accounts for every factor on the previous page.
• Catalysts — A substance that speeds a reaction up, takes part in it, and is there unchanged at the end.
• Reversible Reactions — Reactions that run both ways, and two you can drive backwards and forwards at will.
• Dynamic Equilibrium — Nothing appears to be happening, everything is still happening — and that is what lets conditions shift it.

Topic 4 · Organic chemistry

The chemistry of carbon compounds: crude oil and its fractions, alkanes and alkenes, alcohols, carboxylic acids, esters, and the polymers made from all of them.

• What Organic Chemistry Is — Two facts about carbon generate several million compounds — and three words keep them in order.
• Naming, Drawing And Classifying — A name that tells you the structure, a method that finds every isomer, and three words that cover every organic reaction here.
• Crude Oil And Its Fractions — One mixture, separated by boiling point into six useful materials — and one causal chain that explains every trend down the column.
• Burning Fuels — Two ways a hydrocarbon can burn, and why one of them fills a room with a gas you cannot smell.
• Pollutants And Acid Rain — One pollutant comes out of the fuel and one comes out of the air — and telling them apart decides which fix works.
• Cracking — Breaking long molecules nobody wants into short ones everybody does — and the reason a refinery has to.
• Alkanes — The family that is already full — what saturation means, and the one reaction that gets past it.
• Alkenes — Two hydrogens missing, one double bond gained — and a family that is far more useful for it.
• Alkene Reactions And The Bromine Test — The double bond opens, both bromine atoms join on, and an orange colour disappears — which is how you tell the two families apart.
• Alcohols — One –OH group changes everything about a chain of carbons — and there are three quite different ways to take it further.
• Making Ethanol — Two industrial routes to the same molecule — one grown in a vat, one built from crude oil, and neither obviously better.
• Carboxylic Acids — The –COOH group, the acid reactions it gives, and the reason a bottle of vinegar is on the specification.
• Esters And How To Make One — An alcohol and an acid, a drop of catalyst and some gentle warmth — and a smell that tells you it worked.
• Working Out Esters, And What They Are For — Given the two parents, deduce the ester; given the ester, work backwards — and find out why a strawberry sweet smells of anything at all.
• Addition Polymers — Millions of double bonds opening onto each other, nothing given off — and a material that will not go away afterwards.
• Condensation Polymers — Two reactive ends instead of one, an ester link made over and over, and a molecule of water lost every single time.

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