Find out what type of liquid (pH) breaks down limestone the most

Science Fair Project Information
Subject: Earth Sciences
Grade level: Elementary School - Grades 4-6
Academic Level: Ordinary
Project Type: Experimental
Cost: Low
Awards: Second Place, Canada Wide Virtual Science Fair (2007)
Affiliation: Canada Wide Virtual Science Fair (VSF)
Year: 2007
Description: In order to discover which liquid causes the most erosion in limestone, equal limestone pieces were immersed into 3 different liquids with different pH: hydrochloric acid, vinegar and water. After liquid evaporation, material mass dissolved in each liquid will be calculated: mass of the limestones before immersion (A ) minus the mass of the rocks after evaporation (B) equals the mass of the residue eroded (C).
Link: http://www.virtualsciencefair.org/2007/hill7s2/