Chemistry · GCSE · Acids & Alkalis

Strong & weak acids

ch6Free1:39Heddy Score 3 of 7, below the standard

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What you need to know

  • Strong acids ionise completely in water; weak acids only partly.
  • Strength and concentration are different ideas.
  • A lower pH means a higher concentration of hydrogen ions.

In this clip

0:30–3:34Relative atomic massgcse-chem-5-1-1-6
3:34–5:24Naming compounds and writing equationsgcse-chem-5-1-1-1b
5:53–6:41Mixtures and how to separate themgcse-chem-5-1-1-2
6:41–8:30How the model of the atom developedgcse-chem-5-1-1-3
8:30–10:48Electronic structuregcse-chem-5-1-1-7
12:43–14:41How the periodic table developedgcse-chem-5-1-2-2
14:41–15:18Group 0: the noble gasesgcse-chem-5-1-2-4
15:18–18:16Group 7: the halogens and their trendsgcse-chem-5-1-2-6a
18:16–20:01Group 1: the alkali metalsgcse-chem-5-1-2-5
20:01–22:52States of matter and the forces between particlesgcse-chem-5-2-2-1
22:52–24:00The three types of chemical bondgcse-chem-5-2-1-1
24:00–25:06Covalent bonds and small moleculesgcse-chem-5-2-1-4a
26:05–27:14Properties of metals and alloysgcse-chem-5-2-2-7
27:23–29:19Properties of ionic compoundsgcse-chem-5-2-2-3
29:19–30:06Properties of small moleculesgcse-chem-5-2-2-4
30:06–33:04Giant covalent structuresgcse-chem-5-2-2-6
33:04–34:00Graphene and fullerenesgcse-chem-5-2-3-3
34:00–34:23Polymers as very large moleculesgcse-chem-5-2-2-5
38:06–38:51Relative formula massgcse-chem-5-3-1-2
38:58–39:48Moles — counting by weighingch1
39:48–43:03Reacting masses from equationsgcse-chem-5-3-2-2
43:49–45:44The reactivity seriesgcse-chem-5-4-1-2
45:44–47:53Oxidation and reduction as electron transfergcse-chem-5-4-1-4
47:53–50:00Neutralisation and making saltsgcse-chem-5-4-2-2
50:00–50:45The pH scale and neutralisation in terms of ionsgcse-chem-5-4-2-4
51:58–53:37Strong & weak acidsch6
54:06–55:40Extracting metals by electrolysisgcse-chem-5-4-3-3
55:40–57:15Electrolysis of solutions in watergcse-chem-5-4-3-4
57:15–59:30Exothermic and endothermic reactionsgcse-chem-5-5-1-1
59:30–62:16Bond energy calculationsgcse-chem-5-5-1-3
Also coversIons — atoms with a chargech3
Also coversUncertainty in measurementsgcse-chem-5-3-1-4
Also coversConcentration in grams per cubic decimetregcse-chem-5-3-2-5
Also coversLimiting reactantsgcse-chem-5-3-2-4
Also coversElectrolysis: the processgcse-chem-5-4-3-1
Heddy Score3/7, Below the standard
  • Trusted source · passed. The creator's own upload, live and playable here.
  • On the map · not judged yet. A teacher watched it: it mainly teaches this map topic.
  • Spec-true · not judged yet. Accurate, and right for the current UK specification.
  • Focused · passed. One idea, short enough to watch in one go.
  • Accessible · passed. Good captions, clear sound and pictures.
  • Safe for children · not judged yet. Right for 11 to 16 year olds, with no sales pitch.
  • Proven · not judged yet. Earned from our students: they learn from it, find it helpful and watch it to the end.
★ passed · ☆ pending · ✕ failed
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Our own students' answers. These are what move ★7 Proven.
How the Heddy Score works

Why we picked it

A long whole-paper AQA Chemistry Paper 1 revision run-through, useful for Year 11 revision; later chapters after the combined-science marker are triple-only.

Primrose Kitten Academy | GCSE & A-Level Revision on YouTubechecked 2026-10-16