The Chemistry of Dyeing Easter Eggs

Easter is a favorite time of year for the chemistry buffs at ChemCeed.  What may seem like just a fun family activity is actually a very cool chemical reaction!

The shell of an egg is made up of Calcium Carbonate & Protein (CaCO₃ + N₂H₂).  Our other components in this (unintentional) science experiment are: Water (H₂0), Vinegar (C₂H₄O₂), The Dye: (C18H14N2Na2O8S2), and Protein Molecules.

When we add our hard-boiled egg to vinegar and water, the calcium in the shell reacts with the vinegar to make carbon dioxide (CO2).  Usually, you can see this chemical reaction taking place, as bubbles of CO2 will form in the liquid.  The negatively charged molecules on the protein coating around the eggshell act like a magnet for the positively charged ions and hydrogen proteins from the acidic vinegar.  This helps the dye to stick to and permeate the shell, leaving you and your family with colorful eggs for the holiday!

When you’re dyeing eggs this year, try making it a teachable moment as a fun science experiment and dye some eggs without vinegar to see the difference!