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Activity 2.5 — Metal Carbonate + Acid → CO₂

NCERT Activity 2.5: React calcium carbonate (CaCO₃) with dilute HCl. CO₂ gas evolves. Pass it through lime water — the lime water turns MILKY, confirming CO₂.

How To Perform

1

Add Calcium Carbonate

Put CaCO₃ (chalk / marble chips) in a conical flask.

2

Add Dilute HCl

Pour HCl onto the CaCO₃ — brisk effervescence of CO₂.

3

Observe CO₂ Travel

Gas bubbles through the delivery tube into lime water.

4

Lime Water Test

Clear lime water turns milky white — confirms CO₂.

5

Conclude

CaCO₃ + 2HCl → CaCl₂ + H₂O + CO₂. A double displacement reaction.

⚠️ Safety Notes

  • Wear safety goggles when handling acids.
  • Do not seal the gas exit — pressure can build up and cause splattering.
  • Lime water is mildly caustic — avoid skin contact.