So I performed an experiment to investigate the effect of fluoride ions on the rate of reaction between egg shells (calcium carbonate) and acid.
When doing this I had a dry sample of crushed egg shells and a sample previously soaked in distilled water which had dried for 3 days but was still slightly moist in a 'gloopy' texture.
When I reacted the moist egg shells with hydrochloric acid they made a frothy mixture of bubbles where the carbon dioxide was trapped in bubbles while the dry egg shells fizzed and the carbon dioxide was not trapped in bubbles.
What could be a reason for the differences in the way the carbon dioxide was trapped?
(membranes were removed from both samples)