Why would you remove the egg shell first if it were to be placed in vinegar?

Egg shells is made up of calcium carbonate. Vinegar aka ethanoic acid is a type of acid. When vinegar come upon contact with the egg shell, the egg shell will corrode making it weak and fragile.

In terms of science, this is what happens:

Calcium carbonate + acid will produce calcium salt + water + carbon dioxide

CaCO3 + CH3COOH -> CH3COOCa + H2O + CO2

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