A-Level Chemistry

23:05 Topic 1 Atomic Structure No one has ever seen inside an atom. It is far too small — a single atom is about a million times thinne… 19:02 Topic 2 Atoms, Molecules & Stoichiometry Here is a problem. A single teaspoon of water holds about two hundred thousand billion billion molecules… 15:06 Topic 3 Chemical Bonding Two molecules, almost the same size. Water, and hydrogen sulfide. Sulfur sits directly below oxygen in t… 7:31 Topic 4 States of Matter Diamond melts at three thousand five hundred and fifty degrees Celsius. Iodine melts at one hundred and … 8:21 Topic 5 Chemical Energetics A Bunsen burner gets hot enough to soften glass. An instant cold pack, squeezed once, drops close to fre… 6:34 Topic 6 Electrochemistry & Redox Two pieces of iron. One is quietly rusting on a fence. The other sits inside a battery, pushing electron… 10:12 Topic 7 Equilibria Some reversible reactions never finish. You mix the reactants, the colour changes, and then everything j… 7:13 Topic 8 Reaction kinetics Iron left outside takes years to rust away. Strike a match, and almost the same chemistry — oxygen attac… 8:43 Topic 9 The Periodic Table: chemical periodicity Sodium and argon sit in the same row of the Periodic Table, with only six elements between them. Drop so… 8:01 Topic 10 Group 2 Before a stomach X-ray, the patient is asked to drink a thick white liquid. It is full of barium — and b… 7:28 Topic 11 Group 17 Here are three colourless solutions. They look exactly the same. One is a chloride, one is a bromide, on… 7:40 Topic 12 Nitrogen and sulfur Take a breath. Nearly four fifths of what just went into your lungs was nitrogen — and it came straight … 8:56 Topic 13 An introduction to AS Level organic chemistry Chemists have found more than ten million hydrocarbons and carbon compounds. Ten million. So how can any… 9:54 Topic 14 Hydrocarbons Two clear liquids, both nothing but carbon and hydrogen. And two test tubes of orange bromine water. Sha… 7:31 Topic 15 Halogen compounds Press the button on a can of freezer spray, and your skin goes numb with cold. Inside is a halogenoalkan… 8:20 Topic 16 Hydroxy compounds Squeeze hand sanitiser onto your hands. It feels cold, and then it is gone. That is ethanol — the alcoho… 8:03 Topic 17 Carbonyl compounds Open a bottle of nail polish remover, and that sharp smell is propanone. Your own body makes a little of… 8:02 Topic 18 Carboxylic acids and derivatives Open a bottle of vinegar and you know it at once. That sharp smell is ethanoic acid, and vinegar is only… 7:46 Topic 19 Nitrogen compounds Look at the thread in a jacket, a rope, a pair of stockings: nylon. It is built from two kinds of molecu… 7:24 Topic 20 Polymerisation Look around you. A drinks cup. A shopping bag. A plastic wrapper. All three are made of the same kind of… 8:01 Topic 21 Organic synthesis Look at almost any medicine. It is a complicated molecule, and it began as something simple — often a sm… 8:45 Topic 22 Analytical techniques (AS) You have just made a new compound. It is a clear liquid in a flask, with no label, and you cannot see a … 8:02 Topic 23 Chemical energetics (A2) Sodium is a soft metal that burns in air. Chlorine is a choking, poisonous gas. Put them together and yo… 7:53 Topic 24 Electrochemistry (A2) Two things in your pocket run on the same chemistry. A battery: a reaction that wants to happen pushes e… 7:56 Topic 25 Equilibria (A2) Your blood is held at pH seven point four. Move it a few tenths either way and you are in hospital. Yet … 8:01 Topic 26 Reaction kinetics (A2) Here is a real reaction: hydrogen peroxide reacting with iodide ions in acid. Look at the balanced equat… 8:06 Topic 27 Group 2 (A2) Here is a puzzle. Go down Group 2, from magnesium to barium, and the hydroxides get more soluble. Go dow… 8:24 Topic 28 Chemistry of transition elements Look at these six test tubes: pink, orange, yellow, green, blue, violet. Every one holds a d-block metal… 8:28 Topic 29 An introduction to A Level organic chemistry Two molecules. Same atoms, same bonds. The only difference: one is the mirror image of the other, like y… 7:42 Topic 30 Hydrocarbons (A2): arenes Orange bromine water is the classic test for a double bond. Shake it with an alkene, and the orange colo… 7:56 Topic 31 Halogen compounds (A2) A farmer sprays a field. Many of the pesticides and weedkillers in that tank are halogenoarenes: a chlor… 8:38 Topic 32 Hydroxy compounds (A2): phenol In the eighteen sixties, surgery was terrifying. The cutting could be survived; the infection that follo… 8:08 Topic 33 Carboxylic acids and derivatives (A2) Open a medicine cabinet and pick up a packet of aspirin. That tablet is an ester. At AS you met one smal… 7:49 Topic 34 Nitrogen compounds Look at three very different things. A sweet, dyed bright orange. A painkiller tablet. And the protein i… 7:58 Topic 35 Polymerisation (A2) Look at three very different things. A nylon rope. A plastic drinks bottle. The protein in your own hair… 7:52 Topic 36 Organic synthesis (A2) Three very different things: a bright orange dye, a painkiller, and a tough plastic. All three begin as … 8:06 Topic 37 Analytical techniques (A2): NMR Here are seven different molecules. Every one has five carbons, ten hydrogens and one oxygen, and every …