Amount of substance in use in chemical engineering in the United States is the pound-mole, having the symbol lb-mol. One pound-mole is . When quoting an amount of substance, it is necessary to specify the entity involved, unless there is no risk of ambiguity. One mole of chlorine could refer either to chlorine atoms, as in 58.44 g of sodium chloride, or to chlorine molecules, as in 22.711 liters of chlorine gas at STP. The simplest way to avoid ambiguity is to replace the term "substance" by the name of the entity or to quote the empirical formula. For example: Amount of substance
Inclusion compound is known as a clathrate, not an inclusion complex. In molecular encapsulation, a guest molecule is trapped inside another molecule. Inclusion compound In host-guest chemistry, an inclusion compound is a complex in which one chemical compound (the "host") has a cavity into which "guest" compound can be accommodated. The interaction between the host and guest involves purely van der Waals bonding. The definition of inclusion compounds is very broad, extending to channels formed between molecules in a crystal lattice in which guest molecules can fit. Calixarenes and related formaldehyde-arene condensates are one class of hosts that form inclusion compounds. One