Formula unit Formula unit A formula unit in chemistry is the empirical formula of any ionic or covalent network solid compound used as an independent entity for stoichiometric calculations. It is the lowest whole number ratio of ions represented in an ionic compound. Examples include ionic NaCl and KO and covalent networks such as SiO and C (as diamond or graphite). Ionic compounds do not exist as individual molecules; a formula unit thus indicates the lowest reduced ratio of ions in the compound. A "chemical formula" shows the kinds and numbers of atoms in the smallest representative unit of a substance. In
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