Chemistry · GCSE · Chemical Reactions

Test for chlorine

Test for chlorineFree3:16Heddy Score 3 of 7, below the standard
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What you need to know

  • Gases such as hydrogen, oxygen and carbon dioxide are all colourless, so a chemical test is needed to tell them apart.
  • Chlorine is identified with damp litmus paper: it is bleached white (blue litmus may first turn red).
  • The chlorine test sits alongside the other standard gas tests: a squeaky pop for hydrogen, a relit glowing splint for oxygen and milky limewater for carbon dioxide.
  • Ammonia turns damp red litmus blue, so the colour change on litmus helps separate it from chlorine.

In this clip

Runs 3:16, from 0:00 to 3:16 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

405K views · 3.45K likes · FuseSchool - Global Education 933K subscribers

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

Why we picked it

A short, clear run through the standard gas tests that places the chlorine bleaching test in context with the others students must learn.

FuseSchool - Global Education on YouTubechecked 2026-10-22

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