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Enter your formula using the Hill system:
In the Hill system, the total number of carbon atoms is listed first, followed by the total number of hydrogen atoms, followed by other atoms in alphabetical order.
For example H3C(CH2)8CH2NH2 becomes C10 H23 N (or C10H23N - spaces between the elements are optional)
If there is no carbon in the compound, all the elements are (including hydrogen) listed in alphabetical order.
Multicomponent substances (salts, mixtures, etc.) in the Hill system
Rewrite the formula into Hill order and separate components with a dot, e.g. H2 O4 S . Mg
Polymers in the Hill system
Rewrite each component into Hill order. Put the components inside brackets, separated with full stops, and follow the brackets with an x, e.g. (C8 H8 . C4 H6)x
For monomers, the component is written in Hill order inside brackets, followed by x, e.g. (C8H8)x
Alloys in the Hill system
Elements are listed in alphabetical order, separated by full stops, e.g. Cr . Fe
Further help
There are more detailed instructions on the Hill system on the CAS website.
