The correct order of the listed compounds in terms of increasing solubility in water is:

CaCO3 < Ca(OH)2 < Ca(HCO3)2 < CaCl2 < Ca

Calcium carbonate (CaCO3) is the least soluble compound in water among those listed. As we move down the list, the compounds become increasingly more soluble in water. Calcium chloride (CaCl2) is the most soluble compound in water among those listed.