Seashells in hydrochloric acid

Seashells are dissolved in a liquid.

Scientific name: Calcium carbide reacts with hydrochloric acid.


Shells on Acid

by kkalumuck

Утилизация ракушек в кислоте - химические опыты


Dissolving Seashells

by Niaoson


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Reaction formula

CaCO3 + 2HCl → CaCl2 + H2O + CO2

Step-by-step instruction

  1. Put a few seashells in a petri dish.
  2. Pour hydrochloric acid on the bottom of the petri dish.
  3. Acid dissolves the seashells.

Scientific background

Seashells consist of about 63-94% of calcium carbonate, 2-25% of silicon dioxide and small amount of other admixtures. Calcium carbonate easily reacts with hydrochloric acid with the formation of calcium chloride, water and carbon dioxide.

CaCO3 + 2HCl → CaCl2 + H2O + CO2

This reaction is highly exothermic. The released gas makes the seashells move. Silicon dioxide does not react with hydrochloric acid and remains unchanged.


Published on 15 April 2015

  • Fire
  • Heating with fire
  • Explosion
  • Poisoned gas
  • Organic
  • Electricity
  • Solution
  • Oxidation reduction
  • Color change
  • Precipitate
  • Gassing
  • Catalyst