Examples of index fossils. Index fossils (also known as guide fossils, indicator fossils or zone fossils) are fossils used to define and identify geologic periods (or faunal stages).
Methyl cellulose. Methyl cellulose (or methylcellulose) is a chemical compound derived from cellulose. It is a hydrophilic white powder in pure form and dissolves in cold (but not in hot) water, forming a clear viscous solution or gel.
Solve for x, and you'll know how soluble the compound is. Because of how the solubility constant is defined, your answer will be in terms of moles of the compound dissolved, per liter of water. You may need a calculator to find the final answer. 1  The following is for solubility in pure water, not with any common ions.