The main substance of egg shell is calcium carbonate, and white vinegar is a solution of acetic acid.

When eggs with shells are put into white vinegar, the following reactions will occur:

CaCO3+2ch 3 cooh = Ca(ch 3c oo)2+H2O+CO2

Calcium acetate is dissolved in water and exists in the form of ions in the aqueous solution after the reaction. If there is less hard calcium carbonate in the eggshell, it will become soft.