posted by afghandon .
Equation for the reaction which took place: Hydrochloric acid + calcium carbonate -> calcium chloride + carbon dioxide + water
When the reaction stopped the total mass had decreased from 102.5g to 101.4g.
some water had evaporated from the beaker what else caused the drop is mass?
Some of the CO2 was lost as a gas.
Also, depending on how hot the mixture became, maybe some of the water was lost as steam.