Luobi Cave Luobi Cave Luobi Cave () is a karst cave under the west face of Yin Ridge (印岭) located north east of Lizhigou Town (荔枝沟镇), from Sanya City, Hainan Province, People's Republic of China. The entrance to the cave is approximately high and wide. Inside the apex reaches a height of with a floor area of about Two large stalactites hang down from the roof like large pens, hence the cave's name. A number of inscriptions carved into the walls of the cave are believed to date to the Yuan Dynasty (1271–1368). One of these refers to the precise date of
Calcium carbonate acid to "dissolve" the calcium carbonate. where [A] = [HPO] + [HPO] + [HPO] + [PO] is the total acid concentration. Thus phosphoric acid is more efficient than a monoacid since at the final almost neutral pH, the second dissociated state concentration [HPO] is not negligible (see phosphoric acid). Calcium carbonate Calcium carbonate is a chemical compound with the formula CaCO. It is a common substance found in rocks as the minerals calcite and aragonite (most notably as limestone, which is a type of sedimentary rock consisting mainly of calcite) and is the main component of pearls and the shells