Chemistry · KS3 Y8 · Acids & Alkalis

Acids, alkalis & pH

Acids, alkalis & pHFree4:27Heddy Score 3 of 7, below the standard
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What you need to know

  • Acids form hydrogen ions in aqueous solution.
  • An alkali is a soluble base and forms hydroxide ions in water.
  • The pH scale distinguishes acidic, neutral and alkaline solutions.
  • An acid reacting with an alkali produces a salt and water.

In this clip

Runs 4:27, from 0:00 to 4:27 of the full video.

Heddy Score3/7, Below the standard
See the seven stars
  • 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
Our students

Not enough students yet

Our own students' answers. These are what move ★7 Proven.
On YouTube

418K views · Freesciencelessons 995K subscribers

As reported by YouTube on 2026-11-02. Not part of the Heddy Score.
How the Heddy Score works

Why we picked it

The lesson links acid and alkali definitions to pH and neutralisation.

Freesciencelessons on YouTubechecked 2026-10-18

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