Chemistry · GCSE · Acids & Alkalis

Acids + carbonates

Acids + carbonatesFree1:06Heddy Score 3 of 7, below the standard
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What you need to know

  • When a carbonate reacts with an acid it makes a salt, water and carbon dioxide gas.
  • To test for a carbonate, add dilute hydrochloric acid and bubble any gas given off through limewater.
  • Limewater turning cloudy (milky) shows the gas is carbon dioxide, so a carbonate was present.

In this clip

Runs 1:06, from 0:25 to 1:31 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

536K views · 8.49K likes · Cognito 1.37M 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 crisp explanation of the acid + carbonate reaction and the limewater test that proves carbon dioxide is made.

Cognito on YouTubechecked 2026-10-22

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