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 equilibrium pressure must exceed total atmospheric pressure of 101 kPa, which happens at 898 °C. Calcium carbonate is poorly soluble in pure water (47 mg/L at normal atmospheric CO partial pressure as shown below). The equilibrium of its solution is given by the equation (with dissolved calcium carbonate on the right): where the solubility product for [Ca] [CO] is given as anywhere from "K" = 3.7×10 to "K" = 8.7×10 at 25 °C, depending upon the data source. What the equation means is that the product of molar concentration of calcium ions (moles of dissolved Ca per liter of solution)